BR112020013005B1 - METHOD FOR DETERMINING ELECTROMAGNETIC RADIATION TRANSMITTANCE THROUGH A TRANSPARENT ARTICLE - Google Patents

Abstract

METHOD FOR MEASURING THE OPTICAL CHARACTERISTICS OF A TRANSPARENT ARTICLE. A method for determining the transmittance of a transparent article (250) includes the steps of obtaining a first intensity of electromagnetic radiation reflected or emitted by the reference surface (80) with an intensity measuring device (400), positioning the transparent article ( 250) on the reference surface (80), obtain a measurement of a second intensity of electromagnetic radiation transmitted through the transparent article (250) that is reflected or emitted by a region (110) of the reference surface (80) covered by the article transparent (250) with the intensity measuring device (400); and calculate transmittance using measurements of the first intensity and second intensity.

Description

BACKGROUND OF THE INVENTION Field of invention

[0001] The present invention relates to a method and system for measuring to determine optical characteristics of a transparent article, such as an optical element, for example, a photochromic ophthalmic device, under real and/or laboratory conditions.

Technical considerations

[0002] Optical elements that absorb electromagnetic radiation in the visible region of the electromagnetic spectrum are used in a variety of articles, such as ophthalmic lenses for glasses and sunglasses and contact lenses. Ophthalmic lenses that absorb electromagnetic radiation improve the wearer's viewing comfort and increase the wearer's ability to see in bright conditions. Examples of ophthalmic lenses that absorb electromagnetic radiation include fixed-shade ophthalmic lenses and photochromic ophthalmic lenses.

[0003] Photochromic lenses change hue in response to certain wavelengths of electromagnetic radiation. Photochromic lenses provide the wearer with better vision and comfort when exposed to bright light conditions, but return to a state of non-absorption or lower absorption in low-light conditions. Photochromic lenses provide comfort and ease of viewing in a variety of lighting conditions and eliminate the need to switch between pairs of glasses when moving between low-light/indoor and outdoor/high-light locations.

[0004] Known methods for testing or quantifying the amount of light transmitted by ophthalmic lenses, such as photochromic ophthalmic lenses, use a conventional optical bench under laboratory conditions. The photochromic lens is activated, typically by exposure to ultraviolet radiation, and is affixed to the optical bench for testing. Although optical benches are suitable for laboratory conditions, they may not provide an accurate determination of the optical characteristics and/or aesthetic characteristics of photochromic lenses under real-world conditions, such as when actually used in ambient lighting conditions. The color or tint/darkness of activated photochromic lenses may appear different when actually worn by a user under real-world conditions compared to when the lens is measured on an optical bench under laboratory conditions. Additionally, the perceived aesthetics of photochromic lenses may differ when actually worn due to the variable color and shading characteristics of the human eye.

[0005] Light transmission by photochromic lenses changes based on the amount and duration of actinic radiation received. If the photochromic lens was first activated by a user under ambient conditions and then transferred to a laboratory optical bench for measurement, the level of activation of the photochromic lens may be different between the time it is activated and the time it is affixed. the optical bench for measurement. Existing methods for maintaining activation under laboratory conditions, such as exposing photochromic lenses to xenon arc lamps, may not accurately recreate actual conditions.

[0006] The ability to determine optical characteristics of an ophthalmic lens, for example, an activated photochromic ophthalmic lens, outside of a conventional laboratory environment, has several applications, including in quality control and marketing. Testing photochromic ophthalmic lenses under real-world conditions provides useful data about the comfort and reliability experienced by a wearer. Furthermore, the ability to accurately determine the actual characteristics of photochromic ophthalmic lenses can provide buyers with a quantifiable or qualifiable basis for judging various photochromic ophthalmic lenses for use in their geographic location or for their desired purpose.

[0007] It is further preferred to determine optical characteristics over the area of transparent articles, such as ophthalmic devices, quickly, as it allows the identification of defects in ophthalmic devices. For example, variations in optical densities between various portions of an ophthalmic device can be identified in accordance with the system and method disclosed herein. Furthermore, a photochromic gradient of a photochromic ophthalmic device can also be quickly determined.

[0008] Thus, it would be desirable to provide a method and/or system for measuring optical characteristics of transparent articles, such as a photochromic ophthalmic device, under real-world conditions and/or laboratory conditions. There is an additional need for the method and/or system to be portable.

DISCLOSURE SUMMARY

[0009] A method for determining the transmittance of electromagnetic radiation through a transparent article comprises: measuring a first intensity of electromagnetic radiation reflected or emitted by a reference surface; positioning a transparent article on a portion of the reference surface; measuring a second intensity of electromagnetic radiation transmitted through the transparent article that is reflected or emitted by a region of the reference surface that is covered by the transparent article; and calculating the transmittance of electromagnetic radiation through the transparent article using measurements of the first intensity and the second intensity.

[0010] A method for determining the transmittance of electromagnetic radiation through a transparent article comprising: positioning a non-activated transparent article on a portion of a reference surface; measuring a first intensity of electromagnetic radiation reflected or emitted by a region of the reference surface covered by the non-activated transparent article; activate the transparent article on the reference surface; measuring a second intensity of electromagnetic radiation transmitted through the transparent article that is reflected or emitted by a region of the reference surface that is covered by the activated transparent article; and calculating the transmittance of electromagnetic radiation through the transparent article using measurements of the first intensity and the second intensity.

[0011] A method for determining the transmittance of electromagnetic radiation through a transparent article: measuring a first intensity of electromagnetic radiation transmitted through the transparent article that is reflected or emitted by a region of the reference surface covered by an activated transparent article; measuring a second intensity of electromagnetic radiation reflected or emitted by a region of the reference surface that is not covered by the transparent article; convert the first and second measurements to CIE color coordinates; and calculate the transmittance of electromagnetic radiation through the transparent article using the difference in CIE color coordinates.

[0012] The transparent article may be in direct contact with the ocular surface or may be spaced from the reference surface.

[0013] Measurements of the first and second intensities can be made using a photographic imaging device.

[0014] Electromagnetic radiation can be one or more wavelengths of visible light or one or more wavelength ranges of visible light.

[0015] The transparent article may be an optical element, for example, an ophthalmic device, such as a photochromic ophthalmic device. The photochromic ophthalmic device may be a photochromic RGP contact lens.

[0016] A method for determining the transmittance of a photochromic ophthalmic device at a desired level of activation comprises: selecting a desired wavelength range of electromagnetic radiation; selecting a desired level of activation of the photochromic ophthalmic device; exposing the photochromic ophthalmic device to actinic radiation in the desired wavelength range until the photochromic ophthalmic device reaches the desired level of activation; maximize the visibility of a region of the sclera of an eye; obtaining a first image of the sclera region with an imaging device, wherein the imaging device is configured to record light intensity data over the selected wavelength range; recording a first set of electromagnetic radiation intensity data for the selected wavelength range obtained from the first image; cover or overlap the sclera region with the activated photochromic ophthalmological device; obtaining a second image of the sclera region with the imaging device; recording a second set of electromagnetic radiation intensity data for the selected wavelength range obtained from the second image; insert the first and second data sets into a database; and using a processor to determine the transmittance of the photochromic ophthalmic device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1A is a schematic side view of an exemplary intensity measuring system comprising an intensity measuring device for measuring electromagnetic radiation intensity data reflected from a reference surface;

[0018] FIG 1B is a schematic side view of another exemplary intensity measuring system comprising an intensity measuring device for measuring intensity data of electromagnetic radiation emitted from a reference surface;

[0019] FIG 1C is a schematic side view of yet another exemplary intensity measuring system comprising an intensity measuring device for measuring electromagnetic radiation intensity data reflected from an ocular surface;

[0020] FIG. 2A is a schematic side view of a system for measuring intensity according to FIG. 1A, and including a schematic representation of a transparent article;

[0021] FIG. 2B is a schematic side view of a system for measuring intensity according to FIG. 1B and including a schematic representation of a transparent article;

[0022] FIG 2C is a schematic front view of a reference surface with a transparent article and illustrating a plurality of measuring regions;

[0023] FIG. 3A is a schematic front view of an ocular surface illustrating a measurement region;

[0024] FIG. 3B is a schematic front view of an ocular surface according to FIG. 3A showing an exemplary transparent article on the ocular surface;

[0025] FIG. 3C is a schematic front view of an ocular surface according to FIG. 3A showing an exemplary ophthalmic device on a portion of the ocular surface;

[0026] FIG. 4A is a schematic front view of an ocular surface illustrating another measuring region;

[0027] FIG 4B is a schematic front view of an ocular surface according to FIG. 4A showing an exemplary transparent article on the ocular surface;

[0028] FIG. 4C is a schematic front view of an ocular surface according to FIG. 4A showing an exemplary ophthalmic device over a portion of the ocular surface;

[0029] FIG. 5 is a schematic front view of an ocular surface showing an exemplary positioning of the ophthalmic device;

[0030] FIG. 6 is a block diagram of an exemplary measurement method of the invention;

[0031] FIG. 7 is a block diagram of another exemplary measurement method of the invention;

[0032] FIG. 8 is a block diagram of another exemplary measurement method of the invention; It is

[0033] FIG. 9 is a schematic representation of an ophthalmic device defining a region of interest.

DESCRIPTION OF PREFERRED MODALITIES

[0033] As used in the specification and claims, the singular form of "a", "an" and "the" includes plural referents unless the context clearly indicates otherwise.

[0034] Spatial or directional terms, such as "left", "right", "up", "down" and the like, are related to the invention, as shown in the drawing figures. However, the invention may take several alternative directions and consequently these terms should not be considered limiting.

[0035] All numbers used in the specification and claims are to be understood as modified in all instances by the term "about". By "about" we mean a range of plus or minus ten percent of the declared value.

[0036] The term "as" should be understood as non-limiting. In other words, the elements mentioned after "how" should be understood as non-limiting examples of the characteristics mentioned.

[0037] All ranges disclosed in this document encompass the initial and final range values and any and all subranges included therein. The ranges disclosed in this document represent the average values in the specified range.

[0038] The use of the terms "covered by" or "coverings" with respect to the positional relationship between examples of a reference surface and examples of a transparent article means direct contact. For example, a region of an ocular surface covered by an ophthalmic device means that the ophthalmic device is in direct contact with the ocular surface. It should be understood that the terms "direct contact" and "directly on" also include conditions in which a tear film is present between the ophthalmic device and the ocular surface.

[0039] Likewise, the use of the terms "over", "superimposed" and "superimposed" with respect to the positional relationship between examples of a reference surface and examples of a transparent article means not being in direct contact. For example, an ophthalmic device "on" an ocular surface means that the ophthalmic device is spaced from the ocular surface.

[0040] The term "uncovered" or "uncovered" used with respect to the positional relationship between examples of a reference surface and examples of a transparent article means that the reference surface is neither "covered" nor "overlapped" by an article transparent from the reference frame of an imaging device.

[0041] The terms "polymer" or "polymeric" include oligomers, homopolymers, copolymers, polymer mixtures (i.e., mixtures of homopolymers or copolymers) and terpolymers, for example, polymers formed from two or more types of monomers or polymers.

[0042] The term "ultraviolet radiation" means electromagnetic radiation having a wavelength in the range of 100 nm to less than 380 nm. The terms "visible radiation" or "visible light" mean electromagnetic radiation having a wavelength in the range of 380 nm to 780 nm. The term "infrared radiation" means electromagnetic radiation having a wavelength in the range greater than 780 nm to 1,000,000 nm.

[0043] All documents mentioned herein are "incorporated by reference" in their entirety.

[0044] By "at least" we mean "greater than or equal to". By "not greater than" we mean "less than or equal to".

[0045] Wavelength values, unless otherwise indicated, are in nanometers (nm).

[0046] The term "includes" is synonymous with "comprises".

[0047] The terms "actinic radiation" and "actinic light" mean electromagnetic radiation capable of causing a response in a material, such as transforming a photochromic material from one activation state to another activation state.

[0048] The term "photochromic" means having an absorption spectrum for at least visible radiation that varies in response to the absorption of at least actinic radiation.

[0049] When referring to different conditions, the terms “first”, “second” etc. they do not refer to any specific order or chronology, but rather to different conditions or properties. For illustration, the first state and the second state of a photochromic ophthalmic device may differ with respect to at least one optical property, such as the absorption or linear polarization of visible and/or ultraviolet (UV) radiation. For example, a photochromic ophthalmic device may be cleaned in the first state and colored in the second state. Alternatively, the photochromic ophthalmic device may have a first color in the first state and a second color in the second state.

[0050] The term "optical" means pertaining to or associated with light and/or vision. For example, an article or optical element or device may be chosen from ophthalmic articles, elements and devices, articles, display elements and devices, windows, mirrors and active and passive liquid crystal cell articles, elements and devices.

[0051] The term "ophthalmological" means pertaining to or associated with the eye and vision. Examples of ophthalmic articles or devices include corrective and non-corrective lenses, including single-vision or multi-vision lenses, which may be segmented or non-segmented multi-vision lenses (such as, but not limited to, bifocal lenses, progressive trifocal lenses) , as well as other elements used to correct, protect or improve vision (cosmetic or otherwise), including, without limitation, soft contact lenses, hard contact lenses, intraocular lenses, overlay lenses, ocular inserts, optical inserts, magnifying glasses, protective visors or visors, and rigid gas permeable (“RGP”) lenses. These devices may provide optical correction, wound treatment, drug delivery, diagnostic functionality, cosmetic enhancement or effect, or a combination of these properties. Non-limiting examples of photochromic ophthalmic devices can be found in U.S. Patent No. 7,560,056 to Van Gemert et al. and U.S. Patent Application Publication No. 2006/0227287 to Molock et al. Ophthalmic articles or devices are subsets of transparent articles.

[0052] The term "gas permeable contact lenses" or "RGP" means contact lenses having a water content of less than five percent (5%) and formed entirely from rigid polymeric materials that allow oxygen to pass through from the lens to the cornea and are able to maintain its shape in relation to the eye; Embodiments of such lenses can be manufactured by a turning process.

[0053] The term "fixed tone" means having dyes that are non-photosensitive, that is, they do not respond physically or chemically to electromagnetic radiation in relation to the visually observed color thereof.

[0054] The term "transparent" means that the material has the property of transmitting light without appreciable scattering, so that objects beyond are visible. A transparent article consistent with this disclosure may possess photochromic properties and may become "activated" with respect to a desired wavelength range of light. Unless explicitly stated otherwise, or otherwise indicated by the context, any reference to a "transparent article" in this document includes ophthalmic devices, as defined herein as a subset.

[0055] The term "activated" means that the optical device has been exposed to conditions, such as actinic radiation, and for a sufficient period of time, so that the optical device changes from a first activated state to a second activated state in relation to at least one optical property, such as the absorption or linear polarization of visible and/or ultraviolet (UV) radiation.

[0056] The term "desired level of activation" can be a quantitative or qualitative determination. A desired level of activation of a photochromic ophthalmic device may be the level of activation that such device achieved when exposed to ambient or directed light in a specific environment (wavelength or range of wavelengths) for a selected period of time.

[0057] By CIE color coordinates (e.g., CIE color coordinates may conform to CIE XYZ 1931, 1664, and/or 2004 formats.

[0058] The discussion of the invention may describe certain features as being "particularly" or "preferably" within certain limitations (e.g., "preferably", "more preferably" or "even more preferably", within certain limitations). It is to be understood that the invention is not limited to these particular or preferred limitations, but encompasses the entire scope of the disclosure.

[0059] The invention comprises, consists of, or consists essentially of the following aspects of the invention, in any combination. Various aspects of the invention are illustrated in separate drawing figures. However, it should be understood that this is simply for ease of illustration and discussion. In the practice of the invention, one or more aspects of the invention shown in a drawing figure may be combined with one or more aspects of the invention shown in one or more of the other drawing figures.

[0060] FIG. 1A is a schematic representation of a system for measuring 10 of the invention. The system for measuring 10 includes a reference surface 80, a light source 300, and an imaging device 400.

[0061] The light source 300 emits electromagnetic radiation in one or more wavelengths or in one or more wavelength ranges. Electromagnetic radiation can be visible light. The light source 300 may also emit electromagnetic radiation in one or more other spectrums of electromagnetic radiation, such as the infrared (IR) and/or ultraviolet (UV) spectrums. Although not shown in the figure, multiple light sources 300 may be used. If a plurality of light sources 300 are present, the light sources 300 may emit the same wavelength or wavelength range of electromagnetic radiation, or some of the light sources 300 may emit different wavelengths, ranges, or wavelengths. of electromagnetic radiation wave than other light sources 300 Examples of light source 300 include the sun, in which case the electromagnetic radiation would be external ambient light. Or, the light source 300 may be an artificial light source, such as an incandescent lamp, fluorescent light, compact fluorescent light, or any other light source that emits electromagnetic radiation in a desired spectrum.

[0062] The reference surface 80 can be a natural or artificial surface. The reference surface 80 may be configured to have uniform optical characteristics over the surface, such as color or reflectance. The reference surface 80 may be composed of a two-dimensional field of a preferred and/or uniform color. However, the reference surface can be three-dimensional.

[0063] With reference to FIG. 1A, electromagnetic radiation, e.g., visible light, emitted from the light source 300 is reflected at one or more regions of the reference surface 80. The imaging device 400 captures image data of the electromagnetic radiation reflected from the surface reference surface 80. Imaging device 400 is an intensity sensing device and measures the intensity of electromagnetic radiation reflected from one or more portions of reference surface 80. Intensity data, as a function of position, may be included in the image data obtained by the imaging device 400. It is not necessary for the imaging device 400 to have a high resolution to measure the intensity of electromagnetic radiation reflected by the reference surface 80. However, it is preferred that the imaging device 400 has good photometric linearity. It is further preferred that the imaging device 400 has a high dynamic range. Examples of imaging device 400 include digital cameras, charge coupled devices (CCDs), complementary metal oxide semiconductor (CMOS) sensors, photodiode arrays, photomultiplier arrays, or a single sensor (1X1 array) with optics to focus on any given area size. A further example of an imaging device 400 is a hyperspectral imager, in which the image sensor at each pixel can carry data over the entire spectrum of visible light, not just a band reduced due to filters. The imaging device 400 can capture color or black and white images. An example of a suitable imaging device 400 to serve as an intensity measuring device is a model AVT F-145 B/C Stingray camera, commercially available from Allied Vision Technologies of Exton, Pennsylvania. Images obtained using the high dynamic range (“HDR”) function can also be used, provided that the exposure times and dark values are known and assuming a linear relationship between the exposure time and the measured intensity value.

[0064] Image data, including light intensity and position data, may be stored in the internal memory of imaging device 400. Alternatively, image data may be stored in removable or external memory or in any other known manner. in technique.

[0065] Imaging device 400 is configured to receive image data that includes intensity data of one or more selected wavelengths or one or more wavelength ranges of electromagnetic radiation. For example, imaging device 400 may be configured to receive image data that includes intensity data of one or more selected wavelengths or one or more wavelength ranges of electromagnetic radiation within the range of 1 nm to 1,000 nm. . For example, imaging device 400 may be configured to receive image data that includes intensity data from one or more selected wavelengths or one or more wavelength ranges of visible light. For example, imaging device 400 may receive data about the intensity of electromagnetic radiation in the red, green, and blue ranges. Alternatively or additionally, imaging device 400 may receive electromagnetic radiation intensity data in the cyan, yellow, green and/or magenta ranges. Other wavelength ranges can also be used. It will be understood by one of skill in the art that various manufacturers and imaging devices define these color ranges differently and that specific wavelengths or wavelength ranges for each color and some ranges may overlap. Exemplary ranges for red, green and blue are 635 ± 20 nm, 555 ± 20 nm and 460 ± 20 nm, respectively. Any range or combination of wavelength ranges in the visible light spectrum, which includes wavelengths between approximately 380-780 nm, may be used.

[0066] It is possible to choose specific wavelength ranges of visible light for which data can be obtained. These wavelength ranges may correspond to the colors of specific photochromic dyes present in the optical element, such as a photochromic ophthalmic device, being tested. Wavelengths can be any combination of wavelengths and can be defined by using a filter. A filter 450 corresponding to a selected or desired range or ranges of wavelengths of electromagnetic radiation, e.g., visible light, may be placed between the reference surface 80 and the imaging device 400. The filter 450 limits the incoming light in the imaging device 400 at the desired wavelength or range of wavelengths. Filter 450 may be placed over a lens of imaging device 400. Examples of filter 450 include a band-pass filter, a short-pass filter, a long-pass filter, or other filters known in the art. Filter 450 may be a notch filter centered on one or more wavelengths of electromagnetic radiation in any desired wavelength range. The notch filter can transmit a narrow band of wavelengths of electromagnetic radiation centered on the desired wavelength, while blocking the remainder of the visible light spectrum. The 450 filter may be a three-notch filter. The filter 450 may be a three-notch filter with the notches centered at 635 ± 20 nm, 555 ± 20 nm, and 460 ± 20 nm, respectively. Measurements of intensity values can be made in the same wavelength range as light. The filter 450 can be chosen to match or differ from the color of the reference surface 80.

[0067] FIG. 1B is a schematic representation of an exemplary measuring system 20 of the invention wherein the reference surface 80 includes a light source 300. Non-limiting examples of a reference surface 80 include a backlit sheet of fabric or plastic or a LED panel. A reference surface 80 that includes a light source 300 may be diffusely illuminated. An exemplary reference surface depicted in FIG. 1B may include a diffused white light LED system. The light source comprised by the reference surface 80 may be the only light source of the system 20. However, although not shown in the Figure, it should be understood that the system 20 may include additional light sources 300 that are not comprised by the reference surface 80. reference 80.

[0068] FIG. 1C is a schematic representation of an exemplary measuring system 30 of the invention wherein the reference surface 80 comprises an ocular surface 100. The ocular surface 100 may be an artificial surface that approximates one or more aspects of the human eye, such as temperature. , moisture content, reflectance, color, transmittance, or other physical or optical properties of the human eye. For example, the ocular surface 100 may be a three-dimensional polymeric article having regions that approximate one or more characteristics or features of the human eye, such as the sclera 120, pupil 130, and iris 140. The ocular surface 100 may be the surface of a human eye. The ocular surface 100 may be the surface of an animal eye. The ocular surface 100 may comprise an artificial, diffusely illuminated surface.

[0069] With reference to FIGS. 1A-1B, a first measurement of the intensity of electromagnetic radiation reflected or emitted from the surface 80 is obtained with the imaging device 400. The first measurement may be obtained on a selected portion of the reference surface 80. For example, the first measurement may be obtained over one or more regions 110 of the reference surface 80, as shown in FIG. 2C. Likewise, with reference to FIG. 1C, the first measurement of the intensity of electromagnetic radiation reflected from the ocular surface 100, can be performed with the imaging device 400.

[0070] FIGS. 2A and 2B are schematic representations in accordance with the examples shown in FIGS 1A and 1B, respectively, wherein a transparent article 250 is disposed on, or covers, at least a portion of reference surface 80. Examples of transparent articles 250 include any article with transparent properties in the selected wavelength or range of light lengths. These may include ophthalmic articles, elements and devices - including photochromic ophthalmic devices - display articles, elements and devices, windows, mirrors and active and passive liquid crystal cell articles, elements and devices. When the transparent article 250 has a sufficiently high index of refraction, the transparent article 250 can be placed in a medium, such as water, with a higher index of refraction than air.

[0071] FIGS. 3A and 4A are schematic representations of an ocular surface 100 imposed on the x and y axes. These figures show the ocular surface 100 wherein no portion thereof is covered by a transparent article 250. Referring to FIGS. 1C, 3A and 4A, a first measurement of the intensity of electromagnetic radiation reflected from the ocular surface 100 is obtained with the imaging device 400. The first measurement may be obtained on a selected portion of the ocular surface 100. For example, the first measurement may be obtained over a region 110 of the ocular surface 100. The region 110 may be a region of the sclera 120 of a human eye or may be a region of a three-dimensional article that mimics the sclera 120 of a human eye. Region 110 may include a relatively large area of ocular surface 100. For example, region 110 may include 1 square millimeter (mm2) to 25 mm2, such as 1 mm2 to 10 square millimeters (mm2). The area of region 110 may be substantially equivalent to the area of the transparent article 250, e.g., ophthalmic device, to be measured. Or, the area of region 110 may be greater or less than the area of the transparent article to be measured. FIG. 3A is a schematic representation of the ocular surface 100 in which the region 110 is located on a portion of the sclera 120 that is adjacent to the iris 140 of the ocular surface 100. The region 110 illustrated in Fig. 3A is a curved and elongated region. In Fig. 4A, region 110 is spaced from iris 140. Region 110 illustrated in Fig. 4A is a circular or oval region. It should be understood that region 110 may have any shape. It should also be understood that region 110 may be located on any portion of the ocular surface 100, including but not limited to the iris 140, pupil 130, sclera 120, or any combination thereof.

[0072] FIGS. 3B and 4B are schematic representations of an ocular surface 100, in which a transparent article 250, such as a spectacle lens or other transparent article, is placed over the ocular surface 100. The transparent article 250 may be an ophthalmic device outside the eye - that is, an ophthalmic device that is configured not to be placed in direct contact with an eye. The transparent article 250 may be a fixed-shade ophthalmic device or a photochromic ophthalmic device. When the transparent article 250 is a photochromic ophthalmic device, the photochromic ophthalmic device may or may not be activated. The transparent article 250 may be spaced from the ocular surface (e.g., when the transparent article 250 is an eyeglass lens). The transparent article 250 may overlap all or part of the region 110. If the transparent article 250 is a photochromic ophthalmic device, the photochromic ophthalmic device may be exposed to actinic radiation for a period of time to achieve a desired level of activation. For example, for a period of time to achieve full activation.

[0073] FIGS. 3C and 4C are schematic representations of the ocular surface 100, in which a transparent article in the form of an ophthalmic device 200 is covering the ocular surface 100. The ophthalmic device 200 may be an in-eye ophthalmic device - that is, an ophthalmic device that is configured to be placed in direct contact with one eye. The ophthalmic device 200 may be a fixed-tone ophthalmic device or a photochromic ophthalmic device. When the ophthalmic device 200 is a photochromic ophthalmic device, the photochromic ophthalmic device may or may not be activated. The ophthalmic device 200 may be in direct contact with the ocular surface (e.g., when the ophthalmic device 200 is a contact lens, such as an RGP contact lens). The ophthalmic device 200 may cover all or a portion of the region 110. If the ophthalmic device 200 is a photochromic ophthalmic device 200, the photochromic ophthalmic device 200 may be exposed to actinic radiation on the ocular surface 100 for a period of time to reach a level desired activation. For example, for a period of time to achieve full activation.

[0074] Referring to FIGS 2A - 2C, a second measurement of the intensity of electromagnetic radiation, e.g., visible light, transmitted through the transparent article 250 that is reflected or emitted by the reference surface 80 is made with the imaging device 400 The second measurement includes intensity data over at least a portion of the reference surface region 80 covered or overlapped by the transparent article 250. The area of the reference surface region 80 may be substantially equivalent to the area of the transparent article 250. Or, the area of the reference surface region 80 may be greater than the area of the transparent article 250 or less than the area of the transparent article 250. The wavelength or range of wavelengths measured for the first measurement and the second measurement are preferably the same.

[0075] FIG. 2C is a schematic representation of a transparent article 250 overlying or covering a portion of the reference surface 80, which is imposed on the x and y axes. As shown in the Figure, one or more regions 110 of the reference surface 80 may be chosen. The regions 110 may have a uniform or irregular shape and may comprise all or a subset of the portion of the reference surface 80 that is overlaid or covered by the transparent article 250. Measurements of the intensity of electromagnetic radiation over a desired range of lengths waveforms may be obtained by an imaging device 400 over one or more regions 110 of the reference surface 80. The one or more regions 110 may be chosen randomly or may correspond to portions of the transparent article 250, the light transmittance through which if you want it to be measured.

[0076] When the imaging device 400 captures image data over all or at least a portion of the surface area of the transparent article 250, intensity values across the transparent article 250 can be compared. This comparison is useful in that it allows identification of differences in transmittance across the transparent article 250. This indicates the location of certain image defects in the transparent article 250. This configuration also allows the user to map a transmittance gradient across a transparent article 250 having a photochromic gradient. In this circumstance, the region 110 of a reference surface 80 (such as an ocular surface 100) may correspond in size to the desired area of the transparent article 250 to be measured. Alternatively, several second measurements may be obtained in which the transparent article 250 covers or overlaps different portions of the reference surface 80, and intensity data may be obtained from regions 110 of the reference surface 80 in these images.

[0077] Likewise, with reference to FIGS 3B and 4B, a second measurement of the intensity of electromagnetic radiation, e.g., visible light, transmitted through the transparent article 250 that is reflected or emitted by the ocular surface 100 is made with the device image image 400. The second measurement includes intensity data about at least a portion of the region 110 overlain by the transparent article 250. The area of the transparent article 250 may be substantially equivalent to the area of the region 110. Or, the area of the transparent article 250 may be greater than region 110 or less than region 110. The wavelength or range of wavelengths measured for the first measurement and the second measurement are preferably the same.

[0078] With reference to examples represented schematically in FIGS 3C and 4C, the second measurement of the intensity of electromagnetic radiation, e.g., visible light, transmitted through the transparent article 250 that is reflected by the ocular surface 100 is obtained with the imaging device 400. The second measurement includes intensity data about at least a portion of the region 110 covered by an ophthalmic device 200. The area of the ophthalmic device 200 may be substantially equivalent to the area of the region 110. Or, the area of the ophthalmic device 200 may be greater than region 110 or less than region 110. The wavelength or range of wavelengths measured for the first measurement and the second measurement are preferably the same.

[0079] With specific reference to FIGS. 3A and 3C, the ophthalmic device 200 may cover portions of the sclera 120 even when the central area of the ophthalmic device 200 is positioned over the pupil 130. The region 110 in FIGS. 3A and 3C is located on a portion of the sclera 120 that is adjacent to the iris 140. The region 110 is located close enough to the iris 140 that, when the ophthalmic device 200 is positioned on the ocular surface 100 in an orientation in which the area central portion of the ophthalmic device 200 is positioned over the pupil 130, the region 110 of the sclera 120 is covered by at least a portion of the ophthalmic device 200. For example, covered by a peripheral portion of the ophthalmic device 200. In this configuration, the second measurement is obtained in at least a portion of the region 110 located between the outer peripheral edge of the ophthalmic device 200 and the outer peripheral edge of the iris 140.

[0080] FIG. 4C depicts an example in which the ophthalmic device 200 is positioned to cover a portion of the ocular surface 100 such that the central area of the ophthalmic device 200 does not cover the iris 130. In this configuration, the region 110 of the sclera 120 is fully or partially covered by the ophthalmic device 200, and the second measurement of the intensity of electromagnetic radiation, e.g., visible light reflected by the ocular surface 100, is obtained with the imaging device 400. The intensity data may include data from the central area of the ophthalmic device 200. This is the portion of the ophthalmic device 200 that is most likely to be positioned over a user's pupil 130 during normal wear and tear and therefore may have the greatest effect on the user's experience.

[0081] With further reference to FIGS. 1A-1B and 2A-2B, in order to compare intensity data between the first measurement and the second measurement, position data on the reference surface 80 is determined. A position on the reference surface 80 between the two intensity measurements can be determined by comparing the shape of the reference surface 80 in each image. This can be achieved by visually comparing images and choosing a range of coordinates in each image to be analyzed. Additionally or alternatively, the reference surface may be overlaid with coordinates, such as x-y coordinates, or other identifying marks that may assist in determining position by comparing image data between the first and second measurements in embodiments in which the shape of the reference surface 80 is otherwise uniform. Software stored in the memory of the imaging device 400, or on an external computing device, may be applied by a processor to automatically compare the images in order to determine the region of the reference surface 80 covered or overlapped by the transparent article 250. A processor may be located in the imaging device 400 or an external processor may be used.

[0082] Likewise, with reference to FIGS. 1C, 3A, 3B, 4A and 4B, in order to compare intensity data between the first measurement and the second measurement, position data on the ocular surface 100 are determined. A position on the ocular surface 100 between the two intensity measurements can be determined by comparing the shape of the ocular surface 100 in each image. This can be achieved by visually comparing images and choosing a range of coordinates in each image to be analyzed. Software stored in the memory of the imaging device 400, or on an external computing device, may be applied by a processor to automatically compare the images in order to determine the region of the ocular surface 100 covered or overlapped by the transparent article 250. A processor may be located in the imaging device 400 or an external processor may be used.

[0083] With reference to FIGS. 1C, 3A, 3C, 4A and 4C, in order to compare intensity data between the first measurement and the second measurement, position data on the ocular surface 100 are determined. As above, a position on the ocular surface 100 between the two intensity measurements can be determined by comparing the shape of the ocular surface 100 in each image. This can be achieved by visually comparing images and choosing a range of coordinates in each image to be analyzed. Software stored in memory of imaging device 400, or on an external computing device, may be applied by a processor to automatically compare images in order to determine the region 110 covered by ophthalmic device 200. A processor may be located in the imaging device 400 or an external processor may be used.

[0084] In relation to FIGS. 1C, 3A-3C and 4A-4C, to ensure that intensity data obtained from the same region 110 of the ocular surface 100 is compared when analyzing the first and second measurements, the relative movement between the ocular surface 100 and the viewing device 400 image may be limited between measurements. Relative movement between the ocular surface 100 and the imaging device 400 may be limited by positioning the imaging device 400 on a fixed or portable support, not shown. If the ocular surface 100 is an artificial device, the device may be screwed or locked in place. If the ocular surface 100 is a human eye, the movement of a user's head may be limited by a headrest, chinrest, bite bar, or other mechanism known in the art. In relation to FIGS. 1A-1B and 2A-2B, similar measurements can be obtained to limit the relative movement between the reference surface 80, the transparent article 250 and the imaging device. Such measurements may include fixing the position of the reference surface 80 and/or fixing the position of the transparent article 250.

[0085] FIG. 5 illustrates an example of positioning the ophthalmic device 200, for example, a photochromic contact lens, such as an RGP contact lens, covering an ocular surface 100 in the shape of a human eye. In this example, a user can maximize exposure of the sclera 120 during the first and second measurements. It is preferred that the ratio of the region 110 that is composed of the sclera 120 is as large as possible. The user can maximize exposure of the sclera 120 by looking up and to the left or right. It should be understood that the user may look in other directions, such as left, right, up, down, or directly at the imaging device 400. The imaging device 400 obtains image data, including data on the intensity of electromagnetic radiation reflected from However, to determine the transmittance of the photochromic ophthalmic device 200, the region 110 of the ocular surface 100 that will be covered by the photochromic ophthalmic device 200 during the second measurement is of particular importance. This covered portion may include a pupil 130, iris 140 and/or sclera 120 of an eye. Due to the relative darkness of the iris 140 and the pupil 130, it may be preferred that the region 110 of the ocular surface 100 that will be covered by the photochromic ophthalmic device 200 be composed mostly or entirely of the sclera 120 in order to reduce errors in measurements of intensity. This may be preferred when the dynamic range of the imaging device 400 is relatively low.

[0086] With further reference to FIG. 5, a user maximizes exposure of the sclera 120 of the ocular surface 100, for example, by looking up and to the left or up and to the right. A first measurement of the intensity of electromagnetic radiation reflected from the ocular surface 100 is obtained with the imaging device 400. The exposed portion of the sclera 120 during the first measurement preferably includes the region 110. The ophthalmic device 200 is placed over the region 110 on the ocular surface 100. If the ophthalmic device 200 is a photochromic ophthalmic device 200, the photochromic ophthalmic device 200 is exposed to actinic radiation for a period of time to achieve a desired level of photochromic activation. A second intensity measurement is obtained with imaging device 400. The intensity measurements include data transmitted through ophthalmic device 20 which is located over region 110.

[0087] With reference to FIGS. 1A-1C and 2A-2B, if the transparent article 250 has photochromic properties, the first intensity measurement can be made with the transparent article 250 in place on the reference surface 80 in a first state. The first state can be a non-activated state. The second intensity measurement can be made with the imaging device 400 after the photochromic transparent article 250 is in a second state. The second state may be an activated state. The second intensity measurement may be obtained through a central portion of the transparent article 250. Alternatively, the second intensity measurement may be obtained through a peripheral portion of the transparent article 250.

[0088] Likewise, with reference to FIGS. 4A and 4B, if the transparent article 250 has photochromic properties, the first intensity measurement can be made with the transparent article 250 in place on the ocular surface 100 in a first state. The first state can be a non-activated state. The second intensity measurement can be made with the imaging device 400 after the photochromic transparent article 250 is in a second state. The second state may be an activated state. The second intensity measurement may be obtained through a central portion of the transparent article 250. Alternatively, the second intensity measurement may be obtained through a peripheral portion of the transparent article 250.

[0089] With reference to FIGS. 3C, 4C and 5, if the ophthalmic device 200 is a photochromic ophthalmic device 200, the first intensity measurement may be made with the ophthalmic device 200 in place on the ocular surface 100 in a first state. The first state can be a non-activated state. The second intensity measurement can be made with the imaging device 400 after the photochromic ophthalmic device 200 is in a second state. The second state may be an activated state. The second intensity measurement may be obtained through a central portion of the ophthalmic device 200. Alternatively, the second intensity measurement may be obtained through a peripheral portion of the ophthalmic device 200. Likewise, with reference to FIGS 2A-C, The first intensity measurement may be made with a photochromic transparent article 250 in place on or covering the reference surface in a first state, and the second intensity measurement may be made with the imaging device 400 after the photochromic transparent article 250 is in a second state. The second state may be an activated state.

[0090] As stated above, due to the relative darkness of the iris 140 and the pupil 130, it may be preferred that the region 110 of the ocular surface 100 that will be covered by the photochromic ophthalmic device 200 be composed mostly or entirely of the sclera 120, the in order to reduce errors in intensity measurements. However, it should be understood that the region 110 may be comprised of the iris 140 and/or the pupil 130. According to this configuration, a first image may be obtained including a region 110 of the iris 140 and/or pupil 130; then, an activated photochromic ophthalmic device 200 may be placed covering or overlapping the region 110 and a second image may be obtained including the same region 110. Likewise, with reference to FIGS. 2A and 2C, in examples where a reference surface 80 is colored similarly to an iris 140 or pupil 130, a first image may be obtained including a region 110 of the reference surface 80, then a transparent article 250 may be placed covering or overlapping region 110 and a second image may be obtained including the same region 110. In such examples, it may be preferred to use an imaging device 400 that is more sensitive than a CCD or CMOS detector, such as traditional photomultiplier arrays or silicon photomultiplier matrices. Non-limiting examples of suitable arrays are the silicon photomultiplier array manufactured by SensL of Cork, Ireland, and multi-pixel photon counters manufactured by Hamamatsu Photonics of Hamamatsu, Japan. When using photomultiplier arrays, one should obtain Be careful to avoid damage to the imaging device due to exposure to external conditions.

[0091] Referring to FIGS 1A-1C, wherein the imaging device 400 comprises a CCD, some of the measured intensity values may be partially attributable to dark current in the CCD. The dark current may depend on the temperature in the CCD. The manufacturer of imaging device 400 may provide a table or graph of intensity values in the CCD due to dark current. The intensity attributable to the dark current at various temperatures can be determined by making one or more measurements with the imaging device 400 while the shutter is closed. Temperature measurements can be performed with a temperature measuring device simultaneously with measuring the first and second intensity values. The imaging device 400 may include a temperature measuring device, or an external temperature measuring device may be used.

[0092] In the first and second measurements, intensity data can be obtained over a range of wavelengths or for specific wavelengths. When comparing the data for the two measurements, the following equation can be applied: where TMed is the transmittance of electromagnetic radiation through article 250; IO is the measurement of the first intensity; IT is the measurement of the second intensity; d is the intensity value attributable to the dark current in the intensity measuring device.

[0093] The measured absorbance AMed of the transparent article 250 is defined as

[0094] With reference to FIG. 1B, it should be understood that for examples of the reference surface 80 that emit light in the desired wavelength range, the TMeas calculation returns an accurate value for the transmittance of the transparent article 250. However, with reference to FIGS 1A and 1C, in examples where the measured intensity of electromagnetic radiation in the desired wavelength range is due to reflection from the reference surface 80, such as an ocular surface 100, and not emission thereof, the intensity of the electromagnetic radiation measured in the second measurement passes through the transparent article 250 twice, i.e., once as it travels through the transparent article 250 (such as an ophthalmic device 200) to the reference surface 80 (or, to the ocular surface 100) of the light source 300 and once again when it is reflected from the reference surface 80 (or ocular surface 100) back through the transparent article 250, to the imaging device 400. To correct for electromagnetic radiation passing through the transparent article 250 twice, the measured absorbance AMed is divided by a factor of two to obtain a corrected absorbance value, ACorr, or:

[0095] A value of a corrected transmittance TCorr is calculated as follows: The above equations reduce to:

[0096] It must be understood that transmittance and absorbance are closely related values. Therefore, unless the context explicitly indicates otherwise, any disclosure or teaching in this application regarding the determination of transmittance also refers to the determination of absorbance and vice versa.

[0097] It should be understood that a change in transmittance and/or absorbance can be determined, in which an inactive photochromic transparent article 250 is positioned covering or on a reference surface 80. Next, a first measurement is made. Then the photochromic transparent article 250 is activated with actinic radiation. Then a second measurement is taken. Then the value of transmissivity change or absorbance change is determined.

[0098] The intensity of the electromagnetic radiation emitted by the light source 300 may vary over time. For example, when the method of the invention is practiced in an outdoor environment where the light source 300 is the sun, clouds may pass over the sun between the first and second measurements, affecting the intensity of electromagnetic radiation incident on the ocular surface 100 In order to compensate for variations in the intensity of incident electromagnetic radiation, the imaging device 400 may obtain measurements from a secondary location 150. The secondary location 150 may be on, adjacent to, or near the reference surface 80. In the examples accordingly with FIGS. 1C, 3A, 4A and 5, the secondary location 150 may be on the ocular surface 100 or may be an area adjacent to or near the ocular surface but outside region 110. Referring to FIG. 5, the imaging device 400 may receive intensity data from the secondary location 150 at the same times that the first and second intensity measurements are obtained. The secondary site 150 may be part of the same images or image data sets that include the intensity data from the first and second measurements. The secondary location 150 may be positioned on the ocular surface 100 that does not comprise the region 110. Or, the secondary location 150 may be located elsewhere, such as on a user's face, or on a surface located near the user or near the surface. eyepiece 100. This surface may be configured to reflect electromagnetic radiation of a specific wavelength range. An example of a secondary location 150 may be a colored flap or dot located on a user's face or located near the ocular surface 100 and which acts as a constant reflector. The secondary location 150 may be white, gray, or any color. Another example of a secondary location 150 may be a portion of a user's face that is not covered with a colored flap or dot. FIG. 5 shows an example of the position of the secondary location 150, however, it should be understood that any suitable surface can be used for the secondary location 150.

[0099] Comparisons between measured values of electromagnetic radiation reflected from the secondary location 150 between the first and second measurements can be used to compensate for changes in the intensity of electromagnetic radiation emitted from the light source 300. For example, if the data intensity values obtained from the secondary location 150 indicate a ten percent decrease in the intensity of the electromagnetic radiation emitted from the light source 300 between the first and second measurements, the values of the first intensity (IO) and/or the second intensity (IT) can be set to this amount when determining a measured transmittance (T) and absorbance (AMed), as well as corrected absorbance (ACorr) and corrected transmittance (TCorr). This configuration can be applied by a processor that implements software.

[00100] Examples of software that can be used to analyze intensity data include Igor Pro, developed by WaveMetrics; Image J, developed by the National Institutes of Health; LabVIEW, developed by National Instruments; Origin and OriginPro, developed by OriginLab; and Microsoft Excel, developed by Microsoft Corporation. Additional software can perform intensity data analysis, as known in the applicable art.

[00101] In another exemplary method, a non-activated photochromic transparent element 250 may be placed on or covering a reference surface 80. By "non-activated" is meant that the ophthalmic device 200 has not been exposed to actinic radiation or has not been exposed to radiation. actinic activity of sufficient intensity and/or for sufficient time to be fully activated. The unactivated photochromic transparent element 250 covers or overlaps at least a portion of the region 110. A first set of intensity data is obtained with the imaging device 400 from the region 110 of the reference surface 80 that is covered or overlapped by the photochromic transparent element. unactivated 250. The photochromic transparent element 250 is activated, e.g., fully activated. A second set of intensity data is obtained with the imaging device 400 of region 110 covered or overlaid by the now activated photochromic transparent element 250. Transmittance is determined by comparing the two sets of intensity data.

[00102] In yet another exemplary method, a non-activated ophthalmic device 200 may be placed on or covering the ocular surface 100. By "non-activated" is meant that the ophthalmic device 200 has not been exposed to actinic radiation or has not been exposed to actinic radiation. of sufficient intensity and/or for sufficient time to be fully activated. The non-activated ophthalmic device 200 covers or overlaps at least a portion of the region 110. A first set of intensity data is obtained with the imaging device 400 from the region 110 of the ocular surface 100 that is covered or overlapped by the non-activated ophthalmic device 200 The ophthalmic device 200 is activated, e.g., fully activated. A second set of intensity data is obtained with the imaging device 400 of region 110 covered or overlaid by the now activated ophthalmic device 200. Transmittance is determined by comparing the two sets of intensity data.

[00103] In a further exemplary method, an activated photochromic transparent article 250 is placed on or covering a reference surface 80, wherein the photochromic transparent article 250 does not entirely cover or overlap the reference surface 80. Image data is obtained with the imaging device 400 of the integral reference surface 80. This image data is converted to CIE color coordinates (e.g., CIE XYZ 1931 format, CIE XYZ 1964 format, or CIE XYZ 2004 format) using any process known in the art. CIE X, Y, and Z values of image data from regions of the reference surface 80 that are covered or overlapped by the transparent article 250 and regions that are not covered or overlapped by the transparent article 250 are compared to calculate the change in transmissivity regarding the X, Y and Z color matching functions. It may be preferred to use the CIE Y values as they peak at around 555 nm. Transmittance can be determined according to the following equation: where TY is transmittance of the ophthalmic device 200 determined in accordance with CIE Y values, Yuncovered is the Y value of a portion of the image of the reference surface 80, wherein the reference surface 80 is not covered or overlapped by the transparent article 250, and Yacima is the Y value of a portion of the image of the reference surface 80, wherein the reference surface 80 is covered or overlaid by the transparent article 250. The transmittance using the X and Z values can be determined using the same equation using the X and X values, respectively, in place of the Y values.

[00104] In another exemplary method, an activated ophthalmic device 200 is placed over or covering an ocular surface 100, wherein the ophthalmic device 200 does not cover or overlap the entire ocular surface 100. Image data is obtained with the imaging device 400 of the ocular surface 100 integral. This image data is converted to CIE color coordinates (e.g., CIE XYZ 1931 format, CIE XYZ 1964 format, or CIE XYZ 2004 format) using any process known in the art. The CIE regarding the X, Y and Z color matching functions. It may be preferred to use the CIE Y values as they peak at around 555 nm. Transmittance can be determined according to the following equation: Wherein TY is transmittance of the ophthalmic device 200 determined in accordance with CIE Y values, Yuncovered is the Y value of a portion of the image of the ocular surface 100, wherein the ocular surface 100 is not covered or overlapped by the ophthalmic device 200 , and Yacima is the Y value of a portion of the image of the ocular surface 100, wherein the ocular surface 100 is covered or superimposed by the ophthalmic device 200. The transmittance using the X and Z values can be determined using the same equation using the values X and X, respectively, in place of the Y values.

[00105] FIG. 6 is a block diagram describing the steps of an exemplary method of the invention. Step 1010 includes measuring a first intensity of electromagnetic radiation reflected or emitted by a reference surface 80. This step may be performed with the intensity measuring device 400. Step 1020 includes positioning the transparent article 250 on the reference surface 80 Step 1030 includes measuring a second intensity of electromagnetic radiation transmitted through the transparent article 250 that is emitted or reflected by the reference surface 80. Step 1040 includes calculating a transmittance of electromagnetic radiation through the transparent article 250 using measurements of the first intensity. and the second intensity.

[00106] FIG. 7 is a block diagram describing the steps of another exemplary method of the invention. Step 2010 includes selecting a desired wavelength range of electromagnetic radiation. Step 2020 includes selecting the desired level of activation of a transparent article 250, preferably a photochromic transparent article 250. Step 2030 includes exposing the photochromic transparent article 250 to actinic radiation until the photochromic transparent article 250 reaches the desired level of activation. Step 2040 includes maximizing the visibility of a region 110 of a sclera 120 of an eye. Step 2050 includes obtaining a first image of the region 110 of the sclera 120 with an imaging device 400. The imaging device 400 may be configured to record electromagnetic radiation intensity data over the desired wavelength range. Step 2060 includes recording a first set of electromagnetic radiation intensity data for the desired wavelength range obtained from the first image. Step 2070 includes overlaying the region 110 of the sclera 120 with the activated photochromic transparent article 250. Step 2080 includes obtaining a second image of the region 110 of the sclera 120 with an imaging device 400. Step 2090 includes recording a second set of data of electromagnetic radiation intensity for the desired wavelength range obtained from the second image. Step 2100 includes inserting the first and second sets of data into a database. And step 2110 includes using a processor to determine the transmittance of the photochromic transparent article 250.

[00107] FIG. 8 is a block diagram describing the steps of another exemplary method of the invention. Step 3010 includes selecting a desired wavelength range of electromagnetic radiation. Step 3020 includes selecting the desired level of activation of the ophthalmic device 200, preferably a photochromic ophthalmic device 200. Step 3030 includes exposing the photochromic ophthalmic device 200 to actinic radiation until the photochromic ophthalmic device 200 reaches the desired level of activation. Step 3040 includes maximizing the visibility of a region 110 of a sclera 120 of an eye. Step 3050 includes obtaining a first image of the region 110 of the sclera 120 with an imaging device 400. The imaging device 400 may be configured to record electromagnetic radiation intensity data over the desired wavelength range. Step 3060 includes recording a first set of electromagnetic radiation intensity data for the desired wavelength range obtained from the first image. Step 3070 includes overlaying the region 110 of the sclera 120 with the activated photochromic ophthalmic device 200. Step 3080 includes obtaining a second image of the region 110 of the sclera 120 overlaid with the photochromic ophthalmic device 200 with the imaging device 400. Step 3090 includes recording a second set of electromagnetic radiation intensity data for the desired wavelength range obtained from the second image. Step 3100 includes inserting the first and second sets of data into a database. and Step 3110 includes using a processor to determine the transmittance of the photochromic ophthalmic device 200.

[00108] The invention according to the present disclosure can be further illustrated by the following examples. These examples do not limit the invention. They only intend to suggest ways of practicing the invention. Those skilled in the art of optics, as well as other specialties, may find other ways of practicing the invention. However, these modes should be considered to be within the scope of this invention.

EXAMPLE 1

[00109] Example 1 refers to measuring the transmittance and absorbance of a photochromic contact lens in an external environment.

[00110] Measurements were carried out in accordance with the present invention of an ophthalmic device on an ocular surface on an outdoor test platform in full sunlight. The imaging device was an uncalibrated AVT camera set to an F-number of 8 and was white balanced. The photochromic ophthalmic device tested was a photochromic contact lens impregnated with a broadband absorbing photochromic dye, and values in the red, green, and blue planes were still obtained. The ocular surface was a human eye. No RGB filters were applied to the camera lens. Because the photochromic dye in the object's lens was absorbed over a broad spectrum, an RGB filter was considered unnecessary for measurements according to this example. Image data was analyzed using Igor Pro 6.37. The measured photochromic lens was activated on the eye for 20 minutes in ambient light before measurement. Transmittance values through the photochromic lens were determined based on the difference in intensity data between two images obtained from the eye in question. Since the transmission value was determined based on the light reflected by the eye, the absorbance value was corrected by a factor of two as described above. Intensity values were measured in "counts", which are scaled voltage units. Before measurements, a dark value in the Red, Green and Blue planes was determined.

[00111] The image data also included an area around the user's eye, from which intensity data from a secondary location could be obtained, as described above. The secondary site was located outside the user's eye. Changes in ambient intensity between the two measurements were accounted for based on a percentage change in the intensity data reflected from the secondary location, and a corrective multiplier was determined based on the inverse of this value. The intensity data from the secondary location is referred to as a third intensity measurement - which corresponds to the image data obtained at the time of the first contact lens intensity measurement - and as a fourth intensity measurement, which corresponds to the image data from the secondary location. image obtained at the time of the second contact lens intensity measurement. The values obtained are shown in Table 1 below. The "Corrective Transmittance" is the uncorrected Transmittance value with the corrective multiplier applied. The "Corrected Absorbance" values were obtained from the corrected transmittance values, corrected by a factor of two, as described above. TABLE 1

EXAMPLE 2

[00112] Example 2 refers to measuring the transmittance of photochromic lenses and non-photochromic RGP contact lenses on a reference surface.

[00113] Generally according to this example, a transparent culture cell was placed on the reference surface of the white light LED backlight. The culture cell included several “pockets” into each of which a sample to be measured was placed. Image data was obtained from all pockets simultaneously. Water - preferably deionized water - was added to one or more pockets in the culture cell.

[00114] For non-photochromic lenses, a dark image and a reference image were obtained, as described above. The RGP lenses are then added to the culture cell pockets.

[00115] For photochromic lens samples according to this Example, the transparent culture cell was placed on the white LED-backlit reference surface and the photochromic contact lenses were added. Dark images and first images were obtained. The photochromic lenses were then activated with a UV LED light source for about five minutes.

[00116] The photochromic lenses were activated and a second set of image data was obtained using an imaging device and the transmittance and/or absorbance of the sample lenses was calculated. Since the photochromic lenses covered the reference surface during the first and second image measurements, the calculations according to the present Example are for a change in transmittance.

[00117] Specifically according to Example 2, an AVT F145C camera was used, equipped with a lens from Edmund Optics of Barrington, NJ. The lens was set to f/11 to provide good depth of field and focus was set in the sample tray. The camera was mounted on an optical rail with the front end of the camera housing positioned 67.5 mm from the top of the LED backlit reference surface and centered on the sample to be measured. AVT's SmartView software was used to configure the camera settings. In SmartView software, camera settings are set to F7 0 mode for collecting raw images. The exposure time was set so that the light intensity was below 55,000 counts but above 40,000 counts. "Counts" are a scaled unit of voltage. The number of averages was typically set to 4 and the output was set to RAW16. White balance was allowed to auto-set until values no longer changed, and then white balance levels were disabled.

[00118] The photochromic lens samples were activated by five minutes of exposure to a four-color UV LED light source from Innovations in Optics, powered by a PP420 LED driver operated at about 12 V DC. The UV LED light source had relative emission peaks at 367 nm, 386 nm, 406 nm, and 419 nm. After activation of the photochromic samples, the LED was moved out of position and measurements of the second image were performed within five seconds of removing the UV LED light source. To further control the output of the UV LED, in addition to setting current and percentage brightness values, a Newport aperture was mounted directly in front of the UV LED optics to help reduce the intensity of the UV LED evenly.

[00119] Illumination of the reference surface was performed using an Edmund Optics white light LED with diffuser set to maximum exposure. The reference surface backlight was powered with a separate 24 V DC power supply. An MP-ICS dimmer controller purchased from Edmund Optics was used to vary the backlight LED output, but this was set to maximum output due to the camera's f-stop setting at f/11. The integral system was enclosed in a dark box to prevent stray light from interfering with the images. The front of the box was covered with dark plastic material from ThorLabs, Inc. of Newton, NJ, to remove external stray light effects from room lighting, particularly when the photochromic lens was activated. Data collection and analysis were performed using an Igor Pro software package that utilized an interface to the Igor software developed by Bruxton Corp. from Seattle, WA, to communicate directly with the AVT camera. The camera was connected to the Igor Pro and the exposure time was set to ensure maximum signal without the images being out of scale. The number of image averages was typically set to 4. The UV output of the UV LED light source was measured using an International Light Technologies ILT950 spectral radiometer.

[00120] Transmittance and absorption calculations were made in accordance with the disclosure above. For RGP lenses, reflectance was calculated based on Equation 4.67 (page 121) of Hecht, Optics, 4th Edition, and an estimated transmittance was determined. The refractive index of water was estimated at 1.33. All refractive indices were estimated to be 589 nm and it was assumed that RGP lenses did not absorb visible light.

[00121] Furthermore, the technique according to Example 2 has the advantage of allowing intensity data to be captured on multiple lenses at the same time, as data acquisition with the imaging device is simultaneous on all lenses of the array . Measurements according to Example 2 are cited in Table 2 below: TABLE 2

EXAMPLE 3

[00122] Example 3 refers to measuring the polarization of light according to the present invention.

[00123] Generally, Example 3 includes obtaining a plurality of image data from an environment through a linear polarizer set to various orientations and determining the polarization of light from a region of interest ("ROI") of that image data and/or or the average polarization of the entire image. The polarization of light can be determined relative to various portions of the environment depending on where the ROI is in relation to the image. For example, if the environment to be measured includes a sky, trees, and a lawn, the separate polarization of light measured from the sky, trees, and/or lawn can be determined from the same image data set.

[00124] While a linear polarizer was used in this Example, it is important to note that a circular polarizer can be used. A circular polarizer can be used if the linear polarizer portion faces the object and the fourth wave plate faces the image detector. A circular polarizer may be preferred if the detector has a polarization bias, such as in a traditional high-end DSLR camera.

[00125] Specifically, in accordance with Example 3, external images were acquired using the Stingray 145C camera mounted on a rail and with an Edmund Optics zoom lens with aperture control: (Model M6Z 1212 - 3S, aperture range of 12 .5mm to 75mm). The lens aperture was set to 16, focus to 4.2, and zoom to 20 for all image acquisitions according to this Example. SmartView_110 software was set to a specific white balance, but auto balance was turned off. Exposure was varied depending on external lighting conditions, the high signal to noise ratio (“HSNR”) setting was set to 4 images on average. Frames per second ("fps") were set as variables. The format was full pixel range, RAW 16. ISO800. The camera was rigidly mounted on a 100mm rail with a polarizer on the front. A spirit level was used to level the rail. The images were obtained with the presence of a Melles Griot (“MG”) linear polarizer, mounted on a rotation stage equipped with a micrometer, oriented at 0, 90 and 45 degrees. The 0 degree setting was approximately +/- 1 degree horizontal. A piece of black cloth was wrapped around the lens over the space between the camera lens and the MG polarizer.

[00126] Images were obtained in sets of five, which facilitated overall data acquisition. It also allowed the elimination of bad images due to sudden movements. The polarizer was rotated between each image acquisition. The time base and/or exposure level was changed for each image in order to obtain good images of the high and low intensity regions of the image. Igor Pro software was used to analyze the images. The five images in each set were averaged and the average image was used to calculate polarization values.

[00127] Image sets were obtained in each polarizer orientation. The first image was obtained with the polarizer orientation at 0 degrees. The second set was obtained with the polarizer set to a 45-degree orientation. The third set was obtained with the polarizer set to a 90-degree orientation. The polarization values of the light reflected from the ROI of the images were determined by comparing the intensity data from the average images of the various polarizer orientations. Additionally, image sets were captured at three exposure times: 12 ms ("low exposure"); 100 ms ("average exposure"); and 200 ms (“high exposure”). For this example, image data in the green plane was analyzed. The polarization values obtained according to Example 3 are cited in Table 3 below. TABLE 3

EXAMPLE 4

[00128] Example 4 refers to the analysis of photochromic defects in a photochromic transparent article according to the present invention.

[00129] Generally, Example 4 includes obtaining intensity data from a photochromic ophthalmic device in a non-activated state, exposing the device to actinic radiation, and obtaining image data from the device in an activated state. The photochromic device undergoes fatigue to produce defects. Image intensity data is obtained from the fatigued lens in a non-activated state and again in an activated state. Image intensity data is analyzed to identify photochromic defects in fatigued lenses.

[00130] Specifically, the image data was obtained with a Stingray 145C camera. The camera was controlled using SmartView software. The camera has been set up with white balance turned on. The exposure time was set to 8.8 milliseconds (ms) with 3 averages. Backlighting was accomplished with an Edmund Optics white light LED, which was heated for more than 10 minutes before use. The camera lens was an Edmund Optics model no. Lens 59873, 50mm F/2.0, which has been set to optimal focus and aperture settings on the order of F/8 in order to obtain a good visual image. The camera aperture and circular polarizer have been removed for this Example. The lights in the room were mostly blocked out with light blocking material. A dark image was collected using these settings and conditions.

[00131] A first image measurement was also collected in these settings. The first image measurement was collected with the photochromic ophthalmic device in question, but not activated, on the backlit reference surface.

[00132] The photochromic ophthalmic device in question was activated by exposure to UVA actinic radiation (385 nm) for about five minutes. The UVA light source was an LED system from Innovations in Optics and was controlled using a Lambda LLS5008 power supply set to 0.6 amps and 3.03 V DC. The distance from the UVA light mechanism to the white light LED reference surface was 22.4 mm. The beam size of the UVA light source was 12 cm. The UVA light source was allowed to warm up for more than 10 minutes before use.

[00133] The UVA light source was positioned in front of the photochromic ophthalmic device in question for 5 minutes of activation and then physically moved out of the way in order to obtain the second image of the activated photochromic device. The second measurement was obtained less than five seconds after the UVA light source moved. Spectral irradiance was not collected.

[00134] Another set of first and second image measurements was obtained after fatigue of the photochromic ophthalmic device in question. After fatigue, the experimental setup was configured in the same way to a reasonable approximation (3.03 V DC, 0.6 amps, etc.).

[00135] The samples were visually aligned so that the labels were at the top of the image. Although not performed in this specific example, samples can be tumbled in a tumbling system to produce additional fatigue or remove an anti-reflective coating.

[00136] The analysis software was modified to collect and use the RGB image, and not just the green part of the image. Some image processing was done in Igor Pro in order to make the images viewable correctly, such as scaling the images to 65535 counts - which is a scaled voltage value - count to mimic a 16-bit output image as the images do not processed were 14 bits.

[00137] Since the first images and second images according to Example 4 include the ophthalmic device to be measured, strictly speaking, the calculated transmittance values actually are a change in transmittance. Therefore, when references in Table 4 indicate that the photochromic ophthalmic device darkens to, for example, 20% transmission, this refers to the darkness after removing the non-activated contribution to transmission.

[00138] Data analysis was performed using Delta F calculations with squares of the order of 0.5 mm. These calculations were based on ISO 12311-2013, which is incorporated herein by reference. Portions of the areas of the squares overlapped the areas of neighboring squares. As illustrated in FIG. 9, a region of interest, or ROI, 160 is defined on the subject photochromic ophthalmic device 200. The ROI 160 is subdivided into subregions, or rows, 170. Intensity data is analyzed and analyzed in each row 170.

[00139] To fatigue the ophthalmic devices in question, fatigue chambers were used. These were aluminum chambers with quartz windows and rubber gaskets applied with high vacuum grease to seal the chambers. Two of the cameras stood out more than the other, meaning their direct exposure was slightly different from the other four cameras. All chambers were evacuated to -30”Hg and allowed to rest in vacuum for 1-3 minutes. It was observed that all chambers maintained a vacuum under such a short period of time. All chambers were pressurized with nitrogen to 10-14 psi and allowed to sit under pressure, closed, for 30 seconds to 2 minutes. It was observed that all chambers maintained pressure for this period of time. All chambers were evacuated and filled to 10-14 psi with nitrogen and allowed to sit overnight. The chambers were then evacuated and then refilled with nitrogen. The chambers were then placed outside for sun exposure. With 900 Watt hours of sun exposure, the chambers were brought back inside, evacuated and refilled with nitrogen. The chambers were placed back outside for an additional 900 Watt hours of sun exposure. The chambers were shown to maintain pressure for 1 week. The chambers were checked after 1 week and again after 2 weeks, with a gas exchange at the 1-week mark. At the end of each week, the chambers were shown to maintain pressure at least 8-12 psi above atmospheric pressure), indicating that there was no significant leak.

[00140] The ophthalmic device in question was subjected to a UVA exposure of 1813 Watt in the fatigue chambers.

[00141] After fatigue of the sample ophthalmological device, image analysis was performed so that the data was analyzed at the same magnitude of the absorbance range. Additionally, the photochromic ophthalmic device was measured with the polarizer in one position and the photochromic ophthalmic device was oriented with an inscribed label oriented towards the top of the sample. However, this did not necessarily result in the same exact orientation between measurements.

[00142] By comparing intensity data obtained in a non-activated state with intensity data obtained in an activated state, one can cancel out non-photochromic defects in the ophthalmic device in question and limit the analysis to only photochromic defects

[00143] The absorbance values obtained according to Example 4 in the fatigue state are recited in Table 4 below. The table shows data in the green plane only, but it should be understood that data can be obtained and analyzed in the red and blue planes, or in other image formats. Each data row corresponds to its own row 170 of the image ROI 160, as represented schematically in FIG. 9. As demonstrated in the Table, image data according to the present invention can be analyzed on a pixel-by-pixel level, and so can the photochromic properties of the transparent articles in question. TABLE 4

EXAMPLE 5

[00144] Example 5 relates to the analysis of the transmissivity of transparent articles having a light absorption gradient in a visible spectrum, such as gradient photochromic lenses.

[00145] Generally in accordance with Example 5, image data was obtained from a photochromic ophthalmic device that experienced a photochromic activation gradient when exposed to actinic radiation. A first measurement was carried out on an inactive photochromic ophthalmic device. The device was then activated and a second measurement was performed with the photochromic ophthalmic device activated. Intensity data were analyzed as described below. The photochromic ophthalmic device was subjected to fatigue, as described in detail in Example 4. As above, image data was obtained in both inactivated and activated states, and intensity data between images was analyzed to determine an absorbance value. This method has the benefit of canceling out non-photochromic defects so that photochromic defects and the gradient can be analyzed effectively.

[00146] Specifically, a Stingray 145C camera was configured with white balance enabled, automatically configured in the SmartView software. The exposure time for each image was set to 18-20 ms with 4 averages. A dark image was collected with these settings. A first image was also collected in these settings. The first image was collected with the photochromic ophthalmic device inactive in position.

[00147] The backlighting was performed with a white light LED from Edmund Optics. The camera used a 50mm f/2.0 lens manufactured by Edmund Optics on model no. 59873 The lens has been set to optimal focus and aperture settings (~f/8.0) in order to obtain a good visual image. The lights in the room were mostly blocked out with light blocking material. The camera aperture and circular polarizer were left in place for this Example. The backlight was allowed to warm up for more than 10 minutes before use.

[00148] The photochromic ophthalmic devices in question were activated by exposure for five minutes to a UV LED system from Innovations in Optics. The UV LED system was a "4 color" system that emitted UV light with relative emission peaks at 365 nm, 385 nm, 405 nm, and 415 nm. The UV LED was controlled using a Gardasoft P420 trigger. The values for the current, brightness percentage and actual current values of each LED in the UV LED system (~365 nm/~385 nm/~405 nm/and ~415 nm) were as follows for each LED: 0.2/ 25%/0.04; 0.2/14%/0.01; 0.2/15%/0.02; and 0.3/45%/0.13, respectively. The distance from the UV LED light mechanism to the white light LED reference surface was 36 cm. The beam size of the UV LED source was 9.5 cm. To activate the photochromic ophthalmic device, the UV LED source was moved in front of the photochromic ophthalmic device in question for five minutes of activation and then physically moved out of the way to capture the activated image. Activated images were obtained within five seconds of removing the UV LED source. Spectral irradiance was collected with UVA and UVV values set to 6.8 and 19.8 W/m2, respectively.

[00149] The samples were visually aligned with a name inscribed on the top of the ophthalmic device in order to preserve orientation between measurements. However, this was not always the correct orientation, so the images had to be rotated after the fact during analysis in order to properly perform gradient imaging.

[00150] Changes were made to collect and use the RGB image and not just the part of the image in the Green plane. Optical density images were processed as described above and absorbance calculated: Abs = log(1/T), T = (IT -d)/(IO-d). Some image processing was performed in Igor Pro in order to make the images viewable correctly, such as scaling the images to 65535 counts (a scaled voltage measure) to mimic a 16-bit output image. Actual images are 14-bit.

[00151] The transmissivity values calculated according to this example are, strictly speaking, a change in transmissivity because the inactive state of the lens was used for the first measurement. Therefore, indications that the lens darkens to, for example, 20% transmissivity actually refer to darkness after removal of the inactivated contribution to transmissivity.

[00152] With the use of the RGB filter, the response of the individual RGB channels was changed enough that the green and blue responses could be out of scale without the image showing red correctly. To resolve this issue, the data acquisition software was changed to display the three color planes separately, with the threshold applied to the three images.

[00153] Data analysis was performed using Delta F calculations with squares of the order of 5 mm. Calculations were based on ISO 12311-2013, which is incorporated into this document by reference. Portions of the areas of the squares overlapped the areas of neighboring squares.

[00154] As illustrated in FIG. 9, a region of interest, or ROI, 160 is defined on the subject photochromic ophthalmic device 200. The ROI 160 is subdivided into subregions, or rows, 170. Intensity data is analyzed and analyzed in each row 170. This is useful because the ophthalmic devices 200 in the present Example experience a photochromic activation gradient.

[00155] The absorbance values obtained according to Example 5 for an ophthalmic device with a photochromic gradient in a non-fatigued state are cited in Table 5, below. The rightmost column includes corrected data on absorbance loss. The corrections relate to scaling issues that were not initially apparent when the image was obtained and were made in accordance with methods known in the art. TABLE 5

[00156] Table 6 shows gradient defect data for the same sample after having undergone a fatigue cycle. Generally, the difference between measurements on a set of photochromic devices was 6%. Therefore, a 6% correction was applied. TABLE 6

[00157] The invention may further be characterized by one or more of the following clauses.

[00158] Clause 1: A method for determining a transmittance of electromagnetic radiation through a transparent article 250 comprising: measuring a first intensity of radiation reflected or emitted by at least a portion of a reference surface 80; positioning a transparent article 250 over or covering at least a portion of the reference surface 80; measuring a second intensity of radiation transmitted through the transparent article 250 that is reflected or emitted by at least one region 110 of the reference surface 80 that is overlapped or covered by the transparent article 250; and calculating a transmittance of electromagnetic radiation through the transparent article (250) using measurements of the first intensity and the second intensity.

[00159] Clause 2: The method, according to clause 1, in which the measuring steps are carried out with an intensity measuring device 400, preferably an imaging device.

[00160] Clause 3: The method according to clause 2, wherein the second radiation intensity is reflected by a region 110 of the reference surface 80 and which further comprises: determining an intensity value attributable to the dark current in the intensity measurement 400; and calculate the transmittance of electromagnetic radiation through 1 of the transparent article 250, according to the following equation: where TCorr is the transmittance of electromagnetic radiation through the transparent article 250; IO is the measurement of the first intensity; IT is the measurement of the second intensity; d is the intensity value attributable to the dark current in the intensity measuring device 400.

[00161] Clause 4: The method according to clause 2, wherein the second radiation intensity is emitted by the reference surface 80 and which further comprises: determining an intensity value attributable to the dark current in the intensity measuring device 400 ; and calculate the transmittance of electromagnetic radiation through the transparent article 250, according to the following equation: , where TMed is the transmittance of electromagnetic radiation through the transparent article 250; IO is the measurement of the first intensity; IT is the measurement of the second intensity; d is the intensity value attributable to the dark current in the intensity measuring device 400.

[00162] Clause 5: The method, according to any one of clauses 1 to 4, which further comprises: measuring the first intensity at a first location on the reference surface 80; and measuring the second intensity at the first location on the reference surface 80.

[00163] Clause 6: The method, according to clause 5, further comprising: measuring a third intensity of radiation reflected or emitted from a secondary location 150 simultaneously with measuring the first intensity, wherein the at least one region 110 is different from secondary location 150; measuring a fourth intensity of radiation reflected or emitted from the secondary location 150 simultaneously with measuring the second intensity; comparing the third intensity with the fourth intensity to determine a change in radiation intensity between the measurement times of the first and third intensities and the second and fourth intensities; and compensating for the change in radiation intensity between the measurement times of the first and third intensities and the second and fourth intensities in calculating the transmittance of electromagnetic radiation through the transparent article 250 using the comparison between the third and fourth intensities.

[00164] Clause 7: The method, according to any one of clauses 1 to 6, wherein the intensity measuring device 400 is configured to measure the intensity of electromagnetic radiation within a spectrum of electromagnetic radiation comprising a range of length waveform from 2 nm to 1,000 nm, preferably 380-780 nm.

[00165] Clause 8: The method, according to any one of clauses 2 to 7, wherein the intensity measuring device 400 is configured to measure the intensity of electromagnetic radiation over a spectrum of electromagnetic radiation comprising a range of length 460 ± 20 nm wave.

[00166] Clause 9: The method, according to any one of clauses 2 to 8, wherein the intensity measuring device 400 is configured to measure the intensity of electromagnetic radiation over a spectrum of electromagnetic radiation comprising a range of length wave of 555 ± 20 nm.

[00167] Clause 10: The method, according to any one of clauses 2 to 9, wherein the intensity measuring device 400 is configured to measure the intensity of electromagnetic radiation over a spectrum of electromagnetic radiation comprising a range of length wave of 635 ± 20 nm.

[00168] Clause 11: The method, according to any one of clauses 1 to 10, wherein the measurements of the first and second intensities are from a range of wavelengths selected from the group consisting of 460 ± 20 nm, 555 ± 20 nm and 635 ± 20 nm.

[00169] Clause 12: The method, according to any one of clauses 2 to 11, further comprising applying a filter 450 over a detector of the intensity measuring device 400 before measuring the first and second intensities.

[00170] Clause 13: The method according to clause 12, wherein the filter 450 is centered on a wavelength selected from the group consisting of 460 ± 20 nm, 555 ± 20 nm and 635 ± 20 nm.

[00171] Clause 14: The method according to clauses 11 or 12, wherein the filter 450 is a three-wavelength notch filter.

[00172] Clause 15: The method, according to any one of clauses 1 to 14, wherein the reference surface 80 is an ocular surface 100 comprising a three-dimensional representation of a human eye.

[00173] Clause 16: The method, according to any one of clauses 1 to 14, wherein the reference surface 80 is an ocular surface 100 comprising a human eye.

[00174] Clause 17: The method, according to clauses 15 or 16, wherein the ocular surface 100 comprises at least a portion of a sclera of the eye.

[00175] Clause 18: The method, according to clause 17, further comprising measuring the value of the second intensity on a central portion or a peripheral portion of the ophthalmic device 200.

[00176] Clause 19: A method for determining a transmittance of a photochromic ophthalmic device 200 at a desired level of activation, comprises selecting the desired wavelength range of electromagnetic radiation; selecting a desired level of activation of the photochromic ophthalmic device 200; exposing the photochromic ophthalmic device 200 to actinic radiation until the photochromic ophthalmic device 200 reaches the desired level of activation; maximizing the visibility of a region 110 of a sclera 120 of an eye; obtaining a first image of the region 110 of the sclera 120 with an imaging device 400, wherein the imaging device 400 is configured to record electromagnetic radiation intensity data over the desired wavelength range; recording a first set of electromagnetic radiation intensity data for the desired wavelength range obtained from the first image; covering the region 110 of the sclera 120 with the activated photochromic ophthalmic device 200; obtaining a second image of the region 110 of the sclera 120 with the imaging device; recording a second set of electromagnetic radiation intensity data for the desired wavelength range obtained from the second image; insert the first and second data sets into a database; and using a processor to determine the transmittance of the photochromic ophthalmic device 200.

[00177] Clause 20: The method, according to clause 19, further comprising applying a filter 450 to the imaging device 400 before obtaining the first and second images.

[00178] Clause 21: The method according to clause 20, wherein the filter 450 is centered on a wavelength selected from the group consisting of 460 ± 20 nm, 555 ± 20 nm and 635 ± 20 nm.

[00179] Clause 22: The method according to clauses 20 or 21, wherein the filter 450 is a three-wavelength notch filter.

[00180] Clause 23: A method for determining the transmittance of electromagnetic radiation through an ophthalmic device 200 comprises: positioning an unactivated ophthalmic device 200 over a portion of an ocular surface 100; measuring a first intensity of radiation reflected by a region 110 of the ocular surface 100 superimposed by the ophthalmic device 200; activating ophthalmic device 200; measuring a second intensity of radiation reflected by a region 110 of the ophthalmic device 200 that is overlapped by the ophthalmic device 200; and calculating the transmittance of electromagnetic radiation through the ophthalmic device 200 using measurements of the first intensity and the second intensity.

[00181] Clause 24: A method for determining the transmittance of electromagnetic radiation through a transparent article 250 comprising: measuring a first intensity of radiation reflected or emitted by a region 110 of a reference surface 80 overlaid by an activated transparent article 250; measuring a second intensity of radiation reflected or emitted by a region of the reference surface 80 that is not overlapped by the transparent article 250; convert the first and second measurements to CIE color coordinates; and calculating the transmittance of electromagnetic radiation through the transparent article 250 using the difference in CIE color coordinates.

[00182] Clause 25: The method, according to any one of clauses 1 to 24, in which the transparent article 250 is in direct contact with the reference surface 80.

[00183] Clause 26: The method, according to clause 1, wherein the transparent article 250 is positioned on the reference surface 80 before measuring the first and second intensities, wherein the measurements of the first intensity and the second intensity are obtained from the same image, in which the first intensity is measured from a portion of the reference surface 80 that is not covered by the transparent article 250, in which the second intensity is measured from a portion of the surface reference 80 which is covered by transparent article 250, and the method further comprises: converting the first intensity measurement into CIE XYZ values; convert the second intensity measurement into CIE XYZ values; and determine the transmittance according to the following equation: , wherein TY is the transmittance of the transparent Yacima article 250 determined in accordance with CIE Y values, Yuncorrected is a Y value of the image portion of the reference surface 80 when the reference surface 80 is not covered or overlapped by the article transparent 250 , and Yacima is a Y value of the image portion of the reference surface when the reference surface 80 is overlapped by the transparent article 250.

[00184] Clause 27: A system for measuring 10, 20, 30 to determine a transmittance of a photochromic transparent article 250 comprises a light source 300 and an intensity measuring device 400.

[00185] Clause 28: The system for measuring 10, 20, 30 in accordance with clause 27, further including a reference surface 80.

[00186] Clause 29: The system for measuring 10, 20, 30 in accordance with clauses 27 or 28, wherein the light source 300 is a natural light source or an artificial light source.

[00187] Clause 30: The system for measuring 10, 20, 30 according to any one of clauses 27 to 29, wherein the intensity measuring device 400 comprises an imaging device.

[00188] Clause 31: The system for measuring 10, 20, 30 in accordance with any one of clauses 27 to 30, wherein the intensity measuring device 400 is configured to measure radiation intensity along a radiation spectrum electromagnetic comprising a wavelength range of 380-780 nm.

[00189] Clause 32: The system for measuring 10, 20, 30 in accordance with any one of clauses 27 to 31, wherein the intensity measuring device 400 is configured to measure radiation intensity along a radiation spectrum electromagnetic comprising a wavelength range of 460±20 nm.

[00190] Clause 33: The system for measuring 10, 20, 30 in accordance with any one of clauses 27 to 32, wherein the intensity measuring device 400 is configured to measure radiation intensity along a radiation spectrum electromagnetic comprising a wavelength range of 555±20 nm.

[00191] Clause 34: The system for measuring 10, 20, 30 in accordance with any one of clauses 27 to 33, wherein the intensity measuring device 400 is configured to measure radiation intensity along a radiation spectrum electromagnetic comprising a wavelength range of 635±20 nm.

[00192] Clause 35: The system for measuring 10, 20, 30 in accordance with any one of clauses 27 to 34, further comprising a filter 450 over a detector of the intensity measuring device 400.

[00193] Clause 36: The system for measuring 10, 20, 30 in accordance with clause 35, wherein the filter 450 is centered on a wavelength selected from the group consisting of 460 ± 20 nm, 555 ± 20 nm and 635 ± 20 nm.

[00194] Clause 37: The system for measuring 10, 20, 30 in accordance with clauses 35 or 36, wherein filter 450 is a three-wavelength notch filter.

[00195] Clause 38: The system for measuring 10, 20, 30 according to any one of clauses 28 to 37, wherein the reference surface 80 is an ocular surface 100 comprising a three-dimensional representation of a human eye.

[00196] Clause 39: The system for measuring 10, 20, 30 in accordance with any one of clauses 28 to 37, wherein the reference surface is an ocular surface 100 comprising a human eye.

[00197] Clause 40: The method, according to any one of clauses 1 to 18, wherein the transparent article 250 is a photochromic ophthalmic device 200, preferably a photochromic RGP contact lens, and the method includes at least partially activating the photochromic ophthalmic device 200 between measuring the first intensity and measuring the second intensity.

[00198] Although the disclosure has been described in detail for purposes of illustration based on the currently most practical and preferred aspects, it should be understood that these details are solely for that purpose and that the disclosure is not limited to the aspects disclosed, but is intended to whether to cover modifications and equivalent agreements. For example, it should be understood that the present disclosure contemplates that, to the extent possible, one or more features of any aspect may be combined with one or more features of any other aspect.

Claims (14)

1. Method for determining a transmittance of electromagnetic radiation through a transparent article (250), characterized in that it comprises: measuring a first intensity of radiation reflected or emitted by at least a portion of a reference surface (80) with a intensity measuring device (400); positioning a transparent article (250) over at least a portion of the reference surface (80); measuring a second intensity of radiation transmitted through the transparent article (250) that is reflected or emitted by at least one region (110) of the reference surface (80) that is covered by the transparent article (250) with the intensity measuring device (400); and calculating a transmittance of electromagnetic radiation through the transparent article (250) using measurements of the first intensity and the second intensity, wherein the second intensity of radiation is reflected by the region (110) of the reference surface (80), the method comprising further: determining an intensity value attributable to the dark current in the intensity measuring device (400); and calculate the transmittance of electromagnetic radiation through the transparent article (250) according to the following equation: where: TCorr is the transmittance of electromagnetic radiation through the transparent article (250); IO is the measurement of the first intensity; IT is the measurement of the second intensity; d is the intensity value attributable to the dark current in the intensity measuring device (400) or at which the second radiation intensity is emitted by the reference surface (80), further comprising: determining an intensity value attributable to the dark current in the intensity measuring device (400); and calculate the transmittance of electromagnetic radiation through the transparent article (250) according to the following equation: where TMed is the transmittance of electromagnetic radiation through the transparent article (250); IO is the measurement of the first intensity; IT is the measurement of the second intensity; d is the intensity value attributable to the dark current in the intensity measuring device (400). 2. Method according to claim 1, characterized by the fact that it further comprises: measuring a third intensity of radiation reflected or emitted from a secondary location (150) simultaneously with measuring the first intensity, wherein at least one region (110) is different from the secondary location (150); measuring a fourth intensity of radiation reflected or emitted from the secondary location (150) simultaneously with measuring the second intensity; comparing the third intensity with the fourth intensity to determine a change in radiation intensity between the measurement times of the first and third intensities and the second and fourth intensities; and compensating for the change in radiation intensity between the measurement times of the first and third intensities and the second and fourth intensities in calculating the transmittance of electromagnetic radiation through the transparent article (250) using the comparison between the third and fourth intensities. 3. Method according to claim 1, characterized by the fact that the intensity measuring device (400) is configured to measure the intensity of electromagnetic radiation within a spectrum of electromagnetic radiation comprising a wavelength range of 1 nm to 1,000 nm. 4. Method according to claim 1, characterized by the fact that the intensity measuring device (400) is configured to measure the intensity of electromagnetic radiation over a spectrum of electromagnetic radiation comprising a wavelength range of 460 ± 20 nm. 5. Method according to claim 1, characterized by the fact that the intensity measuring device (400) is configured to measure the intensity of electromagnetic radiation over a spectrum of electromagnetic radiation comprising a wavelength range of 555 ± 20 nm. 6. Method according to claim 1, characterized by the fact that the intensity measuring device (400) is configured to measure the intensity of electromagnetic radiation over a spectrum of electromagnetic radiation comprising a wavelength range of 635 ± 20 nm. 7. Method according to claim 1, characterized by the fact that the measurements of the first and second intensities are from a range of wavelengths selected from the group consisting of 460 ± 20 nm, 555 ± 20 nm and 635 ± 20 nm. 8. Method according to claim 1, characterized by the fact that it further comprises: applying a filter (450) over a detector of the intensity measuring device (400) before measuring the first and second intensities, wherein the filter comprises a three-wavelength notch filter (450). 9. Method according to claim 8, characterized by the fact that the filter (450) is centered on a wavelength selected from the group consisting of 460 ± 20 nm, 555 ± 20 nm and 635 ± 20 nm . 10. Method according to claim 1, characterized by the fact that the reference surface (80) is an ocular surface (100) comprising at least a portion of a human eye and the transparent article (250) is positioned on the ocular surface (100), wherein the ocular surface comprises at least a portion of a sclera (120) of the eye. 11. Method, according to claim 10, characterized by the fact that it further comprises: measuring the value of the second intensity on a central portion or a peripheral portion of the transparent article (250). 12. The method of claim 1, wherein the transparent article (250) is a photochromic transparent article (250) and the method comprises: selecting a desired wavelength range of electromagnetic radiation; selecting a desired level of activation of the photochromic transparent article (250); and exposing the photochromic transparent article (250) to actinic radiation until the photochromic transparent article (250) reaches the desired level of activation, wherein the reference surface (80) is an ocular surface (100) comprising an eye, wherein at least one region (110) is located in a sclera (120) of the eye, wherein the intensity measuring device (400) is an imaging device configured to record electromagnetic radiation intensity data in the desired wavelength range , wherein measuring the first intensity of radiation reflected by the ocular surface (100) with the intensity measuring device (400) comprises obtaining a first image of the region (110) of the sclera (120) with the imaging device (400) , wherein positioning the photochromic transparent article (250) on the ocular surface (100) comprises superimposing the region (110) of the sclera (120) with the activated photochromic transparent article (250), wherein measuring the second reflected radiation intensity by the region (110) of the ocular surface (100) that is overlaid by the photochromic transparent article (250) with the intensity measuring device (400) comprises maximizing the visibility of the region (110) of the sclera (120) and making a second image of the region (110) of the sclera (120) with the imaging device (400) and in which calculating the transmittance of the electromagnetic radiation through the photochromic transparent article (250) using measurements of the first intensity and the second intensity comprises: recording a first electromagnetic radiation intensity data set for the desired wavelength range obtained from the first image; recording a second set of electromagnetic radiation intensity data for the desired wavelength range obtained from the second image; insert the first and second data sets into a database; and using a processor to determine the transmittance of electromagnetic radiation through the photochromic transparent article (250). 13. Method according to claim 1, characterized by the fact that the transparent article (250) is positioned on the reference surface (80) before measuring the first and second intensities, wherein measurements of the first intensity and of the second intensity are obtained from the same image, in which the first intensity is measured from a portion of the reference surface (80) that is not overlapped by the transparent article (250), in which the second intensity is measured from starting from a portion of the reference surface (80) that is overlapped by the transparent article (250), and the method further comprises: converting the first intensity measurement into CIE XYZ values; convert the second intensity measurement into CIE XYZ values; and determine the transmittance according to the following equation: where: TY is the transmittance of the transparent article (250) determined according to CIE Y values; Yuncovered is a Y value of the image portion of the reference surface (80), wherein the reference surface (80) is not overlapped by the transparent article (250); and Yacima is a Y value of the image portion of the reference surface (80), wherein the reference surface (80) is overlapped by the transparent article (250). 14. The method of claim 1, wherein the intensity measuring device is configured to measure the intensity of electromagnetic radiation within a spectrum of electromagnetic radiation comprising a wavelength range of 380780 nm.