KR101164786B1 - Method for evaluating contact lens fitting state - Google Patents

Abstract

PURPOSE: A method for evaluating contact lens fitting state is provided to improve efficiency of contact lens prescription by performing both measurement and observation for contact lens prescription with single equipment. CONSTITUTION: A mire ring optical system(10) measures a corneal curvature of subject. The mire ring optical system includes a mire ring light source(12) and a two-dimensional image element(20). The mire ring light source emits a ring shaped mire ring light to a cornea of subject. A refractive power measurement optical system(50) includes a measuring light source(52), a micro lens array(64) and a two-dimensional image element(66). The measuring light source emits a measuring light for measuring refractive power of subject.

Description

Method for evaluating contact lens fitting state

The present invention relates to a method for inspecting a contact lens, and more particularly, to an image processing technique for detecting a staining pattern of fluresin, and a method for automatically evaluating a fitting state of a contact lens.

In general, the optometry consists of an optical part, an electronic part, and a mechanical part, and the optical part includes a light output optical system that emits a collimation light and a measurement light to the cornea of the eye to be examined, and a light detection optical system that detects light reflected from the cornea. 1 is a view showing the structure of a conventional optometry for corneal curvature measurement, as shown in Figure 1, the optometry is composed of a meiring optical system 120, an imaging optical system 130 and the operation control device 140 If necessary, as a light transmitting means for transmitting the measurement light reflected from the eye 5 to the imaging optical system 130, a reflection mirror, a relay lens, or the like may be further included. The mirroring optical system 120 is for irradiating the light and focus light for the corneal curvature to the corneal surface of the eye to be examined 5, the lighter light source (121a, 121b) for generating the measurement light A miring 128 for allowing the miring measurement light emitted from the miring light sources 121a and 121b to form a ring-shaped image on the cornea of the eye 5, and at the center of the miring 128 A pair of focus light sources 126 and 127 for generating focus light on the left and right sides, and a collimating lens emitted from the focus light sources 126 and 127 and making the focus light passing through the pinholes 124 and 125 into parallel light ( 122, 123, Collimation lenses). A ring-shaped array of light emitting devices (LEDs) may be used as the mirroring light sources 121a and 121b, and the same light emitting devices (LEDs) may be used as the focus light sources 126 and 127. The imaging optical system 130 includes an imaging lens 131 for imaging the mirroring light and the focus light reflected by the eye 5, and an image of the mirroring light and the focus light formed by the imaging lens 131. And a photodetector 132 for converting the signal into an electrical signal. As the photodetector 132, a conventional two-dimensional imaging device may be used. In the optometrist, the miring optical system 120 irradiates light necessary for measurement to the cornea of the eye to be examined 5, and the imaging optical system 130 detects an image of the light reflected from the eye to be examined 5 as an electrical signal. In operation, the arithmetic and control unit 140 calculates a corneal curvature value by applying a predetermined calculation algorithm to the electrical signal.

On the other hand, the contact lens fitting is made up of steps such as paperweight, anterior segment inspection, corneal curvature measurement, base curve selection, fitting evaluation, and prescription. The questionnaire is to secure the information of the subject's personal information, medical history, etc. in advance through a query, and the anterior eye examination is a process of checking the state of the eye, such as the eyelid, eyelashes, and cornea. Corneal curvature measurement is a process of examining the central curvature and refractive index of the eye, using an optometry such as an optometry, a keratometer, a topography, and the like, and selecting a base curve to select a contact lens suitable for the measured corneal curvature. To choose. The fitting evaluation is a process of evaluating whether the selected lens fits well in the examination through a fluorescein pattern, lens movement and positioning, and is generally performed using equipment such as a button lamp or a slit lamp microscope. Based on the evaluation results, the optometrist prescribes a suitable contact lens in the eye.

Fluresin pattern observation involves injecting fluresin into the subject, applying the lens to be evaluated in the subject, and observing the attachment state of the subject and the lens using a slit lamp microscope. It is using the properties of the resin. If the tear in the eye turns green in response to flurecin, the tear distribution of the eye, specifically, the tear distribution between the cornea and the lens, can be more clearly observed, and the contact lens fitting state can be evaluated therefrom. 2A to 2C are photographs showing the fitting state of the contact lens with respect to the model eye, and the fitting state of the contact lens is generally stiff (FIG. 2A), flat (FIG. 2B), alignment (FIG. 2C). ) Can be separated. As the stiff is applied with a lens whose curvature is too small, the lens periphery and the cornea are in close contact with each other, and tears are collected in the central portion, which makes it difficult to circulate tears and to remove impurities and to supply additional oxygen. In the flat, a lens with too large curvature is applied, excessive tears are distributed around the lens, and the center portion is in close contact. The subject feels discomfort in the eyelid, dry cornea, and the center of the lens as the subject moves. There is a risk of departure. Alignment is the most ideal form, with even tears evenly distributed between the cornea and the lens. The slit lamp microscope mainly used for fluorescein pattern observation is composed of an optical part and a mechanical part, and in some cases, may include an electronic part such as camera equipment. In slit lamp microscopes, observation of the fitting state is performed either directly through the eyepiece or indirectly through camera equipment and monitors, and the optometrist observes the fluresin pattern based on his experience and knowledge and fits the lens. The status should be judged and evaluated subjectively.

As described above, in the conventional contact lens fitting, two kinds of devices for measuring and observing are required, and in particular, the observation equipment only displays the magnified image of the eye to be examined and provides no convenience information. In addition, by using the two kinds of separate equipment, the arrangement of the equipment of the optometrist is complicated, the experience and skill of the optometrist is not required for the use of the equipment, and the overall optometry process is not performed effectively.

Accordingly, it is an object of the present invention to provide a method capable of automatically evaluating the fitting state of a contact lens without depending on the experience and skill of the optometrist. Another object of the present invention is to provide a method capable of quickly and accurately evaluating a fitting state of a contact lens. It is still another object of the present invention to provide a method for evaluating a contact lens fitting state that can improve the efficiency of the contact lens prescription and improve the working environment by performing both measurement and observation for contact lens prescription using a single device. To provide.

In order to achieve the above object, the present invention comprises the steps of detecting the pupil and the iris area in the eye; Reacting with the fluorescent substance administered in the eye, irradiating the eye with visible light capable of confirming the distribution state of the fluorescent substance, to obtain a stained image of the eye; Converting the stained image into a monochromatic image proportional to a distribution of fluorescent material; Detecting an interface, a center, and a radius of a contact lens worn in the eye, from the monochrome eye image; From the center of the contact lens, a 1/4 to 1/2 radius inner region of the contact lens radius is set to the central portion W of the lens optical portion, and the rest of the outer portion is the peripheral portions W1, W2, ... Wi ... Wn. Dividing the contact lens into two regions; And calculating the degree of dyeing (Ck) of the center portion of the contact lens, comparing the result with a standard range, and evaluating the fitting suitability of the contact lens.

Here, the dyeing degree (Ck) is preferably a ratio of the area (Wg) of the pixels having a color intensity greater than a predetermined value in the central area with respect to the central area (W). In addition, the degree of dyeing (Ci) is obtained from the peripheral portion (Wi) of the contact lens, and the edge width (Ei), which is a distance between the center of gravity and the lens boundary point of pixels having a degree of dyeing of a predetermined value or more, is calculated, and then this is a standard range. Evaluating the fitting suitability of the contact lens, or calculating the degree of dyeing Ci at the peripheral portion Wi of the contact lens, and comparing it with a standard range to evaluate the fitting suitability of the contact lens. It is desirable to.

According to the method for evaluating the contact lens fitting state according to the present invention, since corneal curvature and refractive power measurement and observation of the contact lens fitting state can be performed in one device, the efficiency of contact lens prescription is improved, and the experience and skill of the optometrist are improved. Regardless, the fitting state of the contact lens can be evaluated consistently.

1 shows the structure of a conventional optometry for measuring corneal curvature.
2a to 2c are photographs showing the fitting state of the contact lens to the model eye.
3 is an optical circuit diagram showing the configuration of an optometry to which the contact lens fitting state evaluation method of the present invention can be applied.
4 is a flow chart showing the steps of detecting the pupil and iris area in the eye.
5 is a view showing an image of an eye obtained by irradiating white light in the eye.
6 is a view for explaining a process of obtaining the interface P between the pupil and the iris and the interface R between the iris and the peripheral portion in the image of the eye to be examined.
7 is a color coordinate system for forming a monochromatic image of intensity proportional to the degree of color development of a fluorescent material in one embodiment of the present invention.
8 is a view for explaining a process of obtaining the interface K of the contact lens in the image of the eye to be examined;
9 is a diagram for describing a method of detecting a distribution pattern of a fluorescent material in a contact lens region.
FIG. 10 is a flowchart illustrating a process of determining a contact lens fitting suitability by detecting a pattern in which a fluorescent material is distributed in a pupil and an iris region according to the present invention. FIG.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

3 is an optical circuit diagram showing a configuration of an optometry to which the method for evaluating the contact lens fitting state of the present invention can be applied. As shown in FIG. 3, the optometrist to which the method of the present invention can be applied includes a miring optical system 10 for measuring corneal curvature of the eye, a cloud optical system 30 for releasing the control of the eye, and a refractive power of the eye. A refractive power measurement optical system 50 to measure and a color observation optical system 70 for obtaining a visible light image of the eye to be examined and the contact lens worn in the eye are included.

In the automatic ophthalmometer according to the present invention, the miring optical system 10 includes a light source 12 and an eye 5 for emitting light having a ring shape to the cornea of the eye 5. And a two-dimensional imaging device 20 for detecting a mirroring light image reflected from the cornea, and the arithmetic and control unit 7 includes a position of a ring-shaped mirroring light detected by the two-dimensional imaging device 20. And the alignment state and corneal curvature of the eye to be examined 5 can be calculated from the size. The calculation of corneal curvature can be used with conventional algorithms for each device. In addition, if necessary, the mirroring optical system 10 is a first and second to separate and reflect the optical signal of the other optical system (30, 50, 70) and the mirroring light emitted from the mirroring light source 12 The dichroic separation mirrors 14, 17, one or more relay lenses 16, an imaging or objective lens 18, etc. that transmit and / or focus the miring light may be further included.

The refractive power measuring optical system 50 includes a measuring light source 52 for emitting the measuring light for measuring the refractive power of the eye 5, and the measuring light is reflected from the retina of the eye 5 and the eye 5 A microlens array 64 for dividing and condensing the refracted signal light into a plurality of signal lights, and a two-dimensional imaging device 66 for detecting an image of the divided signal lights, and detecting the two-dimensional imaging device 66. From the image of the received signal light, the refractive power of the eye 5 can be measured. In addition, if necessary, the refractive power measurement optical system 50 reflects the measurement light passing through the Badal lens 54 and the badal lens 54 such that the focus of the measured light is focused on the main surface of the eye 5. The measurement light reflecting mirror 56, and the reflected measurement light is polarized, and the polarized beam splitter 58 reflected by the eye 5 is measured, and the measurement light linearly polarized by the polarized beam splitter 58 is examined. (5) an objective lens 60 for focusing the signal light reflected or scattered by the retina, an imaging lens 62 for converging the focused signal light, so that an image of the signal light is formed in a predetermined region, and the like. It may further include.

The cloud optical system 30 is fixed to the image film light source 32, the eye to be examined 5, the image for releasing the adjustment is fixed, the light emitted from the video film light source 32 passes And an image film 34 for forming and outputting an image film image, and an adjusting lens 36 for adjusting a focal length of the image generated by the image film 34, and adjusting the adjustment lens 36. The refractive power of the eye to be examined 5 can be fixed by preventing the image film image from being imaged or imaged at the focal position of the eye to be held 5, thereby fixing the eye of the eye 5 and releasing the adjustment of the eye 5. Ensure this is measured accurately. In addition, if necessary, the cloud optical system 30 is a dichroic separation for separating the optical signals of the relay lens 40, 16, and the other optical system 50, 10, 70 for transmitting, reflecting, focusing or passing the image film image Mirrors 14, 17, 38, and the like.

The color observation optical system 70 is a visible light source (72a, 72b, 74a, 74b) for irradiating one or more visible light to the eye 5 and 2 for detecting the image of the visible light irradiated to the eye 5 And a visible light image (white, colored or color display) of the eye 5 and the contact lens worn on the eye in the two-dimensional image device 76. It is used for lens fitting evaluation. Here, the visible light sources 72a, 72b, 74a, 74b are administered to the white light sources 72a, 72b and / or the eye 5 to emit white light for observing the state of the eye 5 more clearly. It is preferable that they are blue light sources 74a and 74b which react with the fluorescent material and emit visible light, for example, blue light, which can confirm the position of the fluorescent material. As the visible light sources 72a, 72b, 74a, and 74b, light emitting diodes (LEDs) emitting visible light of a corresponding wavelength may be used. In addition, if necessary, the color viewing optical system 70 may share the optical elements of the other optical system 50, 10, 70, for example, visible light of the visible light source (72a, 72b, 74a, 74b) A first dichroic separation mirror 14 which reflects an image, an image film 34 of the haze optical system 30, and a miring light image of the infrared optical system 10, but transmits a signal light image of the refractive power measurement optical system 50, A second dichroic separation mirror 17 reflecting the light image of the miring optical system 10 but transmitting the visible light image and the image film image, and a third dichroic separation mirror reflecting the image film image but transmitting the visible light image (38). Here, the dichroic separation mirror serves as a beam splitter for separating the light according to the wavelength, and the light reflection and transmission ratio thereof are light of the appropriate brightness for each optical system 10, 30, 50, 70. It can be set properly to obtain an image. In addition, the color observation optical system 70 may further include a relay or imaging lens 40, 16, 77, 78, a reflection mirror 79, or the like, which transmits, reflects, focuses, or passes the visible light image as necessary. have. The two-dimensional imaging device 76 transforms the visible light image into an electrical signal and transmits the same to the arithmetic control device 7, and the arithmetic control device 7 analyzes the visible light image using a predetermined algorithm, and transmits the analysis result to an optometrist. to provide.

Next, a method for evaluating a contact lens fitting state according to the present invention will be described. The method for evaluating the contact lens fitting state of the present invention includes (i) detecting the pupil and the iris region in the eye, and (ii) evaluating the fitting suitability by detecting a pattern in which the fluorescent material is distributed in the pupil and the iris region. do. 4 is a flowchart for explaining a step of detecting a pupil and an iris region in an eye to be examined. As shown in FIG. 4, first, a fluorescent substance such as fluorescein (fluorescein) is applied to the test object (S 10). Specifically, a fluorescent substance (dyeing solution) is applied to the eye conjunctiva of the eye (including the model eye) in which the corneal curvature K is measured, and then the contact lens for examination is worn. The optometrist instructs the lens to be located at the apex of the cornea, i.e., the pupil center, instructing the subject's eyes to blink as needed. In this state, the white light is irradiated to the eye under the use of the white light sources 72a and 72b and the two-dimensional image device 76 of FIG. 3 to obtain a first image of the eye to be examined (S 12). The pupil is colored while absorbing most of the white illumination, and since the average brightness varies in the order of the pupil <iris <white and the upper and lower gums, it is used to distinguish each region on the first image.

Next, if necessary, gray scaling is applied to the first image stored in the RGB color color, and the color information of each pixel is converted into intensity information, and then the pupil and the iris region are detected. FIG. 5 is a diagram showing an image of an eye obtained by irradiating white light into an eye, and as shown in FIG. 5, positions of four white illumination images (signal light) reflected from the eye, [(x1, y1) to (x4). , y4)] and set their center points (x0, y0) as starting positions (S14). Next, if necessary, fine noise is eliminated using a morphology operation consisting of an erosion operator and a dilation operator, and a signal light is removed using a closing operator. (S 16). At the boundary between the pupil, the iris, and the white, the brightness of the image changes drastically, so that each region can be identified by the difference in the gray level (brightness) value from the surrounding pixels. To this end, for example, a gradient mask having a 5x5 window size is set in the first image, so that the first image is divided into pixels small enough to distinguish a pupil and an iris region. Next, as shown in Fig. 6, n (e.g., 8 to 24) radiations d1 to at a predetermined angle (e.g., 15 to 45 degrees) from the starting positions x0 and y0. dn) and on the radiation di on the radiation di by applying a general edge search algorithm such as zero crossing to the profile obtained by convolution with the gradient mask. Two edges are detected: the boundary between the pupil and iris (pi) and the iris between the iris and white. On the n radiations, if the coordinates of the respective boundary points are obtained, the interface P = {P1, P2,... Pi… , Pn} and the interface between the iris and the periphery R = {R1, R2,... Ri… , Rn} can be obtained (S 20). As such, when the coordinates of the boundary surface P of the pupil and the iris are obtained, a general circular fitting algorithm or the like is applied to the coordinates, and thus, the center points Xp and Yp of the circle (boundary surface P), that is, the center of the pupil. The coordinates and the radius of the pupil are calculated (S 22).

As such, when the pupil and the iris region are detected, the pattern in which the fluorescent substance (dyeing solution) is distributed in the pupil and the iris region is detected to determine the contact lens fitting suitability. FIG. 10 is a flowchart illustrating a process of determining a contact lens fitting suitability by detecting a pattern in which a fluorescent material is distributed in a pupil and an iris region according to the present invention. As shown in FIG. 10, first, a test is performed using visible light, for example, the blue light sources 74a and 74b shown in FIG. 3, which react with a fluorescent substance administered in the test to identify the position of the fluorescent substance. A blue light (Blue LED) is irradiated inside to obtain a second image (dyed image) of the eye to be examined (S30). When fluresin is used as the fluorescent material, it reacts with light having a blue wavelength and emits green fluorescent light, and emits brighter and brighter green in proportion to the amount of fluorescent material distributed in the eye. Therefore, when the lens curvature is smaller than the curvature of the cornea (a steep prescription), the peripheral portion of the cornea is pressed, and a fluorescent material gathers at the center of the lens, resulting in a strong green pattern. On the other hand, if the curvature of the lens is greater than the curvature of the cornea (flat prescription), the center of the cornea is pressed and the lens is in close contact with the cornea, so that the lens center has a color close to the pupil, like a ring along the periphery of the lens. A green pattern appears. That is, as the lens is flat or stiff, each fluorescent material pattern becomes clear and the distribution area of the pattern is expanded. If the curvature of the lens is suitable for the curvature of the cornea (Alignment prescription), a weak green pattern appears in the entire area of the lens, and a narrow annular green pattern appears along the boundary of the lens.

As such, after obtaining the second image of the eye, the image is converted into a single color image proportional to the distribution amount of the fluorescent substance (S 32). FIG. 7 is a color coordinate system for forming a monochromatic image of intensity proportional to the degree of color development (i.e., the degree of dyeing) of a fluorescent material according to an embodiment of the present invention, as shown in FIG. When the most ideal color generated by is defined as a vector u having three components of R, G, and B, and the color of one pixel on the stored second image is a vector v, two vectors v and u point to The monochrome image may be formed by generating an image having a color level corresponding to the distance between two points. Specifically, in the color coordinate system of the RGB color, as the Euclidean distance D (v, u) between the two points indicated by the two vectors v and u is smaller, the pixel of the image is the color of the bright fluorescent material. (For example, green), and the degree of distribution of fluorescent material is high. Therefore, when the size of D (u, v) is equal to or less than the threshold value D0, a color level g standardized in the range of 1 to 255 may be defined to be inversely proportional to the size of D (u, v), from which the second On each two-dimensional array f (x, y) corresponding to the image, at each pixel, by giving a standardized color level g (x, y) instead of the original RGB color value, the second image is monochromatic (fluorescent) in the color image. To the image of the material color). This scaling process can adjust the contrast of the second image to an appropriate level, and converts 3 bytes of RGB color information into 1 byte of single color information, thereby making it easier and faster to detect the dyed area. can do.

Next, the boundary surface, the center point, and the radius of the contact lens are detected from the monochromatic eye image of the intensity proportional to the distribution amount of the fluorescent substance (S 34). 8 is a view for explaining a process of obtaining the interface K of the contact lens in the monochrome image of the eye to be examined. As shown in Fig. 8, on the second image of the monochromatic eye, the interface R = {R1, R2,... Between the iris and the periphery. Ri… , Rn} forms n radiations d1 to dn toward the centers of the pupils Xp and Yp, detects abrupt changes in color levels on the radiations d1 to dn, and detects the detected points in the lens. Determine the boundary point Ki of. In determining the boundary point Ki, a general edge search algorithm such as that used for detection of the pupil and the iris region can be used. Further, the interface K of the contact lens thus obtained is K = {K1, K2,... Ki… , Kn}, by applying a general circular fit algorithm, the lens center points X1 and Y1 are obtained, and the lens radius Rc is calculated. On the other hand, depending on the degree of adhesion between the eye and the lens, the fluorescent substance may not be distributed along the actual interface of the lens. In this case, to find a more accurate interface, the general circular detector method can be further used. Specifically, from the approximate lens center points (X1, Y1) on the image g (x, y), the green level values of all pixels on the circumference of radius r are normalized by dividing by 2πr and expressed as a rate of change with respect to the radius. . The center points Xc and Yc and the radius Rc when the change value of the circumference is maximum can be used as more accurate lens shape information. That is, according to the conventional circular detector method, if the sum of the normalized green level values of all pixels located on the circumference of each radius is obtained, the rate of change of the green level with respect to the radius can be calculated, where the rate of change becomes the maximum. A circle formed by the radius can be detected as lens shape information. Here, if necessary, when the distance (error) between the center of the contact lens ((X1, Y1) or (Xc, Yc)) and the center of the pupil (Xp, Yp) is large, by adjusting the position of the contact lens, It is preferable to match the center of the contact lens ((X1, Y1) or (Xc, Yc)) with the center of the pupil (Xp, Yp) (S 36).

Next, the distribution pattern of the fluorescent material in the contact lens region is detected to evaluate the contact lens fitting state. 9 is a diagram for describing a method of detecting a distribution pattern of a fluorescent material in a contact lens region. As shown in Fig. 9, first, from the centers X1 and Y1 of the contact lens, a region of 1/4 to 1/2 radius, preferably 1/3 radius, of the lens radius Rc is moved to the center of the lens optical unit. (W), the rest of the outside is set to the peripheral portions W1, W2, ... Wi ... Wn, and the contact lens is divided into two regions. Then, the degree of dyeing (Ck) of the center portion of the contact lens is calculated and compared with the standard range, and the fitting suitability of the contact lens is evaluated. Specifically, the ratio of the area Wg of the pixels having the color intensity (green level value) effective in the central area (that is, the degree of dyeing is a predetermined value or more) with respect to the central area W of the lens and / or these The dyeing degree (Ck) of the lens center is calculated from the average color intensity (green level value) of S 40. When the standard range of the degree of staining when the space between the lens center and the cornea is appropriate is C1 to C2, the calculated degree of staining (Ck) is compared with the threshold C2 (S 42), and the degree of staining (Ck) is the threshold C2. If larger, the curvature of the lens is determined to be stiff, and the degree of stiffness is determined from the difference between Ck and C2 (S 44).

On the other hand, by dividing the periphery of the contact lens into n regions, for each of the divided zones W1, W2, ... Wi ... Wn, the dyeing degree Ci is obtained in the same manner as in the center, The distance Ei between the center of gravity of the pixels having a predetermined brightness or more, that is, the degree of dyeing is a predetermined value or more and the lens boundary point is defined as the edge width Ei of the fluorescent material pattern on the lens interface (S 46). In the lens peripheral portion Wi, if the standard range of the distance between the center of gravity of the fluorescent material and the lens boundary point is E1 to E2, the calculated edge width Ei is compared with the threshold value E2 (S 48). If the width Ei is larger than the threshold value E2, the curvature of the lens is determined to be flat, and the degree of flatness is determined from the difference between the edge width Ei and the threshold value E2 (S50). Alternatively, the standard range of color intensity when the space between the lens periphery Wi and the cornea is appropriate is referred to as C3 to C4, and the degree of dyeing (Ci) at the periphery of the lens is compared with the thresholds C3 and C4 to determine the The degree of stiffness or flatness can be determined. If, at the center and periphery of the contact lens, the degree of dyeing (Ck) is in the standard range, or at the periphery of the contact lens, the edge width (Ei) is in the standard range, that is, the contact lens is either stiff or flat ( If not included in the flat) condition, the current lens curvature is determined to be an alignment suitable for the cornea of the eye to be examined (S 52).

In addition, if necessary, the base of the contact lens suitable for the eye examination using the corneal curvature values K1 and K2 of the eye to be calculated in the corneal curvature measuring step of the optometrist and the contact lens fitting state values (stiffness or flatness) described above. The curve value K 'may be calculated. Although the present invention has been described through specific embodiments, it should be understood that the present invention is not limited to the above-described embodiments and includes various modifications and improvements within the scope of the following claims.

Claims (7)

Detecting the pupil and iris area in the eye;
Reacting with the fluorescent substance administered in the eye, irradiating the eye with visible light capable of confirming the distribution state of the fluorescent substance, to obtain a stained image of the eye;
Converting the stained image into a monochromatic image proportional to a distribution of fluorescent material;
Detecting an interface, a center, and a radius of a contact lens worn in the eye, from the monochrome eye image;
From the center of the contact lens, a 1/4 to 1/2 radius inner region of the contact lens radius is set to the central portion W of the lens optical portion, and the rest of the outer portion is the peripheral portions W1, W2, ... Wi ... Wn. Dividing the contact lens into two regions; And
Calculating a degree of dyeing (Ck) of the center portion of the contact lens, and comparing it with a standard range to evaluate the fitting suitability of the contact lens. The method of claim 1, wherein the dyeing degree Ck is a ratio of an area Wg of pixels having a color intensity greater than or equal to a predetermined value in the central area with respect to the central area W. 3. . The method of claim 1, wherein the degree of dye Ci is obtained from the peripheral portion Wi of the contact lens, and the edge width Ei, which is a distance between the center of gravity and the lens boundary point of pixels having a degree of dye greater than or equal to a predetermined value, is calculated. And comparing it with a standard range to evaluate the fitting suitability of the contact lens. The method of claim 1, further comprising calculating a degree of dye Ci at the peripheral portion Wi of the contact lens, and comparing the same with a standard range to evaluate the fitting suitability of the contact lens. . The method of claim 1, wherein the converting the dyed image into a monochromatic image comprises: defining the most ideal color generated by the color development of the fluorescent material as a vector u having three components of R, G, and B, and When the color of one pixel on the image f (x, y) is called a vector v, an image g (x, y) of a color level corresponding to the distance between the two points indicated by the two vectors v and u is generated. Which is carried out, the method of evaluating the contact lens fitting state. The method of claim 1, wherein the detecting of the interface of the contact lens comprises forming radiations d1 to dn toward the center of the pupil from the interface between the iris and the periphery on the image of the monochrome eye. d1 to dn), which is performed by detecting a sudden change in color level and determining the detected point as the boundary point of the lens. The method of claim 1, wherein the detecting of the pupil and the iris region comprises irradiating white light with the eye, obtaining an image of the eye, and then setting out radiations d1 to dn outward from the center of the pupil, The method of evaluating a contact lens fitting state, which is performed by detecting two points where the color level changes abruptly on the image.

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