JP7841373B2 - Ophthalmic devices and ophthalmic programs - Google Patents

Description

This disclosure relates to an optometry device and program for measuring the refractive power of an eye being examined.

A refractive power measuring device is known that projects a measurement beam onto the fundus of the eye being examined, receives the reflected light beam from the fundus with a light-receiving element, and measures the objective refractive power of the eye being examined based on the output of the light-receiving element (Patent Document 1). For example, in this refractive power measuring device, the distance from the corneal apex of the eye being examined to the lens-fitting reference position assuming the eye is wearing glasses (corneal apex distance) is set to a predetermined distance in advance.

Furthermore, a subjective optometry device is known that measures the subjective refractive power of an eye by using an eye refractive power measurement unit placed in front of the eye being examined, arranging optical elements such as spherical lenses or cylindrical (astigmatism) lenses in the examination window of the eye refractive power measurement unit, and presenting a visual target to the eye through the optical elements (Patent Document 2).

At the start of subjective ophthalmoscopic measurement using a subjective ophthalmoscopic device, the initial correction value (i.e., initial value) of the refractive power measurement unit is set based on the objective refractive power so that the eye being examined is corrected to a predetermined refractive power. Furthermore, the intervertex distance of the corneal vertices of the eye being examined is adjusted to a constant distance. Subjective measurement proceeds under these conditions, and the subjective refractive power is obtained.

Japanese Patent Publication No. 2006-187483 Japanese Patent Application Publication No. 5-176893

Incidentally, if the corneal vertex distance measured objectively differs from the corneal vertex distance measured subjectively, even if an initial value is set based on the objective refractive power of the eye and the prescribed refractive power is applied to the eye, the actual refractive power applied may differ from the prescribed refractive power. For example, in such cases, there were problems in smoothly performing subjective measurements, such as the time required to obtain subjective refractive power.

This disclosure aims to provide an optometry device and program that can smoothly perform subjective measurements of the eye being examined, in light of the above-mentioned problems.

To address the above issues, this disclosure features the following configuration.

(1) An optometry device according to a first aspect of this disclosure comprises: a target presentation means for emitting a target light beam toward the eye to be examined; and a correction means for changing the optical properties of the target light beam; and is an optometry device for subjectively measuring the refractive power of the eye to be examined, characterized by comprising: an objective refractive power acquisition means for acquiring the objective refractive power of the eye to be examined in an objective measurement; a first distance acquisition means for acquiring the first distance from the corneal apex of the eye to the lens fitting reference position in the objective measurement; a second distance acquisition means for acquiring the second distance from the corneal apex of the eye to the lens fitting reference position in the subjective measurement; a conversion means for converting the first objective refractive power based on the first distance to the second objective refractive power based on the second distance when the first distance and the second distance are different; and an output means for outputting the second objective refractive power.

(2) An optometry program according to a second aspect of the present disclosure is an optometry program used in an optometry device that subjectively measures the refractive power of an eye, and includes a target presentation means for emitting a target light beam toward an eye to be examined, and a correction means for changing the optical properties of the target light beam, characterized in that it is executed by the processor of the optometry device to cause the optometry device to execute: an objective refractive power acquisition step for acquiring the objective refractive power of the eye to be examined in an objective measurement; a first distance acquisition step for acquiring a first distance from the corneal apex of the eye to be examined to a lens fitting reference position in the objective measurement of the eye to be examined; a second distance acquisition step for acquiring a second distance from the corneal apex of the eye to be examined to a lens fitting reference position in the subjective measurement of the eye to be examined; a conversion step for converting a first objective refractive power based on the first distance to a second objective refractive power based on the second distance when the first distance and the second distance are different; and an output step for outputting the second objective refractive power.

(3) An optometry device according to a third aspect of this disclosure is an optometry device for measuring the refractive power of an eye to be examined, comprising: objective refractive power acquisition means for acquiring the objective refractive power of the eye to be examined in an objective measurement; first distance acquisition means for acquiring the first distance from the corneal apex of the eye to be examined to the lens fitting reference position in the objective measurement; second distance acquisition means for acquiring the second distance from the corneal apex of the eye to the lens fitting reference position in a subjective measurement; conversion means for converting the first objective refractive power based on the first distance to the second objective refractive power based on the second distance when the first distance and the second distance are different; and output means for outputting the second objective refractive power.

This is an external view of the subjective eye examination device according to this embodiment. This is a schematic external view showing the front and rear views of the refractive power measurement unit according to this embodiment. This is a diagram showing the corneal positioning unit. This is a diagram showing the configuration of the aiming scale plate and the reticle plate. This is a schematic diagram of the control system in a subjective optometry device. This is a flowchart illustrating the process of subjective measurement. This is a diagram showing the configuration of an objective eye refractive power measurement device and a subjective eye examination device. This diagram shows the aiming scale and reticle plate used to confirm the position of the corneal apex. This is a schematic diagram of the first distance in objective measurement and the second distance in subjective measurement. This diagram shows the image sensor positioned within the corneal positioning unit. This is an external view of a subjective optometry device.

<Overview>
Embodiments of the ophthalmic device according to this embodiment will be described below. The items classified in <> below can be used independently or in relation to each other.

The optometry device of this embodiment may be a subjective optometry device that subjectively measures the refractive power of the eye being examined. For example, the refractive power of the eye being examined may be measured by at least one of the following: spherical power, cylindrical power, astigmatism axis angle, etc. Of course, in addition to refractive power, the subjective optometry device may also measure binocular vision function (e.g., at least one of the following: prism amount, stereopsis function, etc.), contrast sensitivity, etc.

<Means for presenting visual targets>
The optometry apparatus of this embodiment may include a target presentation means (for example, a target presentation unit 60). The target presentation means emits a target light beam toward the eye to be examined.

For example, the target presentation means may be a display (e.g., display 61). Alternatively, for example, the target presentation means may be a light source and a DMD (Digital Micromirror Device). Furthermore, for example, the target presentation means may be a light source and a target board.

For example, the target light beam from the target presentation means may be directly guided toward the eye under examination. Alternatively, for example, the target light beam from the target presentation means may be guided toward the eye under examination via a light projection optical system (e.g., light projection optical system 230). For example, the light projection optical system may have at least one optical element for guiding the target light beam emitted from the target presentation means. As an example, it may have at least one of a lens, a mirror, etc.

<Correction means>
The optometry device of this embodiment may include a corrective means. The corrective means alters the optical properties of the target light beam emitted from the target presentation means. For example, the corrective means may be located in the optical path of the projection optical system and alter the optical properties of the target light beam.

The correction method should be configured to change the optical properties of the target light beam.

For example, the correction means may include an optical element. For instance, the optical element may be at least one of the following: a spherical lens, a cylindrical lens, a variable focus lens, a cross-cylinder lens, a rotary prism, a wavefront modulation element, etc. Of course, the optical element may be different from these. In this case, the optical properties of the target beam are changed by controlling the optical element.

Furthermore, the corrective means may have a configuration for optically changing the presentation position (presentation distance) of the target relative to the eye under examination. For example, it may have a configuration for moving the target presentation means along the optical axis, or a configuration for moving an optical element (e.g., a spherical lens) in the optical path along the optical axis. In this case, the optical properties of the target beam are changed by controlling a driving means for controlling at least one of the target presentation means and the optical element.

Furthermore, the corrective means may be, for example, an ocular refractive power measurement unit (e.g., ocular refractive power measurement unit 50) that switches and positions optical elements (e.g., optical elements 46) in front of the eye being examined via an examination window (e.g., examination window 53). For example, the ocular refractive power measurement unit may have a lens disc (e.g., lens disc 45) in which multiple optical elements are arranged on the same circumference. In this case, the optical characteristics of the target light beam are changed by controlling a driving means (e.g., drive unit 56, drive unit 57, etc.) for controlling the lens disc.

<Methods for obtaining objective refractive power>
The optometry apparatus of this embodiment may include an objective refractive power acquisition means (for example, a control unit 70). The objective refractive power acquisition means acquires the objective refractive power of the eye being examined in an objective measurement. For example, the objective refractive power may be at least one of the following: spherical power, cylindrical power, astigmatism axis angle, etc.

For example, the objective refractive power acquisition means may acquire the objective refractive power input by the examiner's operation means (e.g., controller 71). Alternatively, the objective refractive power acquisition means may read an identifier for each subject and acquire the objective refractive power stored in that identifier. As an example, the identifier may be an ID, string, one-dimensional code, two-dimensional code, color code, etc. Furthermore, the objective refractive power acquisition means may acquire the objective refractive power by receiving data measured using an eye refractive power measuring device that objectively measures the refractive power of the subject's eye by projecting a measurement light beam onto the fundus of the subject's eye and receiving the reflected light beam of the measurement light beam reflected by the fundus.

In the above-described refractive power measuring device, the first distance (described later) from the corneal apex position to the lens fitting reference position in the objective measurement of the eye under examination may be pre-set as a predetermined distance. For example, the first distance is pre-stored and set in the device as a standard distance (reference value) of 12 mm, which is generally considered the ideal corneal apex distance in Japan. Of course, the first distance may be a value other than 12 mm. The first distance may be set as a fixed reference value, or it may be set as a reference value that can be arbitrarily changed by the examiner. In this case, the objective refractive power acquisition means may receive at least one of the following data based on the first distance: spherical power, cylindrical power, astigmatism axis angle, etc.

<First distance acquisition means>
The optometry device of this embodiment may include a first distance acquisition means (for example, a control unit 70). The first distance acquisition means acquires a first distance from the corneal apex position of the eye under examination to the lens fitting reference position in the objective measurement of the eye under examination. For example, the lens fitting reference position in the objective measurement may be a position where the spectacle lens is assumed to be positioned when the eye under examination is fitted with spectacle lenses. For example, the lens fitting reference position may be a position separated by a standard distance (reference value) from the corneal apex position of the eye under examination.

For example, the first distance acquisition means may acquire the first distance input by the operator's operation of the control means. Alternatively, the first distance acquisition means may read the identifier for each subject and acquire the first distance stored in the identifier. Furthermore, the first distance acquisition means may acquire the first distance by receiving data from the aforementioned refractive power measuring device. In this case, the first distance acquisition means and the objective refractive power acquisition means may be used interchangeably, receiving objective refractive power data along with the first distance data.

<Second distance acquisition means>
The optometry device of this embodiment may include a second distance acquisition means (for example, a control unit 70). The second distance acquisition means acquires a second distance from the corneal apex position of the eye under examination to the lens fitting reference position in the subjective measurement of the eye under examination. For example, the lens fitting reference position in the subjective measurement may be a position that assumes the spectacle lens will be positioned when the eye under examination is fitted with spectacle lenses. For example, if the optometry device includes an eye refractive power measurement unit, the position where the optical element of the lens disk closest to the eye under examination is positioned may be used as the lens fitting reference position.

For example, the second distance acquisition means may acquire the second distance input by the operator's operation of the control means. Alternatively, for example, the second distance acquisition means may acquire the second distance based on the detection result detected by the detection means described later. Furthermore, for example, the second distance acquisition means may acquire the second distance pre-set as a fixed value in the subjective optometry device.

<Conversion method>
The optometry device of this embodiment may include a conversion means (for example, a control unit 70). The conversion means converts the first objective refractive power based on the first distance to the second objective refractive power based on the second distance when the first objective measurement distance and the second subjective measurement distance are different. For example, the conversion means may convert the first objective refractive power to the second objective refractive power using a conversion table or calculation formula for converting the first objective refractive power to the second objective refractive power. Alternatively, for example, the conversion means may convert the first objective refractive power to the second objective refractive power by adding a conversion amount to the first objective refractive power using a conversion table or calculation formula for obtaining a conversion amount for converting the first objective refractive power to the second objective refractive power.

For example, the aforementioned conversion amount and the second objective eye refractive power may be obtained such that the shift in the focusing position of the target light beam caused by the difference between the first objectively measured distance and the second subjectively measured distance is corrected by such a conversion table or calculation formula. For example, the conversion table or calculation formula may be obtained in advance from experimental or simulation results, etc., and stored in a memory device.

The conversion means may convert the first objective refractive power to the second objective refractive power when the difference between the first objective distance and the second subjective distance exceeds a predetermined threshold (predetermined distance). For example, the predetermined threshold for the difference between the first and second distances may be set as a fixed value in advance, or it may be set by the examiner at an arbitrary value.

The conversion means may convert the first objective eye refractive power to the second objective eye refractive power when the first objective eye refractive power measured at a different distance from the second objective eye refractive power measured at a different distance, and when the first objective eye refractive power measured at a different distance exceeds a predetermined threshold (a predetermined refractive power). For example, the predetermined threshold for the first objective eye refractive power may be set as a fixed value in advance, or it may be set at an arbitrary value by the examiner. Furthermore, for example, the predetermined threshold for the first objective eye refractive power may be set for the direction in which the first objective eye refractive power is negative, or for the direction in which it is positive. Of course, the predetermined threshold for the first objective eye refractive power may be set for either the negative or positive direction of the first objective eye refractive power.

In this embodiment, the conversion means may convert the first objective refractive power to the second objective refractive power according to the values of the first objectively measured distance and the second subjectively measured distance. Alternatively, in this embodiment, the conversion means may convert the first objective refractive power to the second objective refractive power based on a determination result of whether the first objectively measured distance and the second subjectively measured distance are different. In this case, the optometry device may include a determination means for determining whether the first objectively measured distance and the second subjectively measured distance are different. For example, an acceptable range may be provided for the difference between the first and second distances, and if the difference exceeds this acceptable range, it may be determined that the distances are different.

<Detection method>
The optometry device of this embodiment may include a detection means. The detection means detects the second distance in the subjective measurement of the eye being examined. This makes it easy to determine whether the second distance in the subjective measurement matches the first distance in the objective measurement.

The detection means can be configured to measure the distance from the eye under examination to the lens fitting reference position. For example, the detection means may be an image sensor for imaging the eye under examination, and the distance may be detected by analyzing the image captured by the image sensor. Alternatively, for example, the detection means may project an indicator light beam onto the cornea of the eye under examination and measure the distance using an alignment indicator image based on the reflected light beam reflected by the cornea. In other words, the detection means may be an alignment optical system. Furthermore, for example, the detection means may emit a light signal toward the eye under examination and measure the distance by detecting the reflected signal. In other words, the detection means may be an optical detector. Also, for example, the detection means may emit ultrasound toward the eye under examination and measure the distance by detecting the reflected wave of the ultrasound reflected by the eye. In other words, the detection means may be an ultrasonic detector. Of course, other optical systems and detectors may also be used.

<Output method>
The optometry apparatus of this embodiment may include an output means (for example, a control unit 70). The output means outputs the second objective refractive power, which is obtained by converting the first objective refractive power by the conversion means.

For example, the output means may output the second objective refractive power to set the initial correction value of the correcting means. In this case, the optometry device may include a correction control means (e.g., a control unit 70) that sets the initial correction value of the correcting means based on the second objective refractive power output from the output means. For example, the initial correction value of the correcting means may be the value of the second objective refractive power. That is, it may be the correction value for correcting the eye under examination with the second objective refractive power. Alternatively, for example, the initial correction value of the correcting means may be a value different from the second objective refractive power and may be a correction value calculated based on the second objective refractive power. For example, it may be the correction value for correcting the eye under examination with a refractive power that uses the second objective refractive power as a guideline. As an example, it may be the correction value for correcting with a refractive power obtained by adding or subtracting a predetermined step (e.g., 0.25D) from the second objective refractive power.

The correction control means only needs to be able to change the refractive power of the eye being examined based on the initial correction value. For example, the target presentation means may be moved along the optical axis based on the initial correction value. Alternatively, for example, the optical elements in the optical path of the target beam may be moved or inserted/removed relative to the optical axis based on the initial correction value. If the optometry device includes an eye refractive power measurement unit, the optical elements of each lens disk may be switched and arranged based on the initial correction value. By controlling at least one of the target presentation means and optical elements in this way, the eye being examined is corrected to a predetermined refractive power at the start of the subjective measurement, allowing the subjective measurement to be performed smoothly.

For example, the output means may output the second objective refractive power to prompt the examiner to set the initial correction value of the correction means. In this case, the optometry device may include a display control means that causes information based on the second objective refractive power output from the output means to be displayed on a display means. Furthermore, in this case, the optometry device may also include a print control means that causes information based on the second objective refractive power output from the output means to be printed on a printing means.

Furthermore, the information based on the second objective eye refractive power may be the value of the second objective eye refractive power, or the initial correction value of the corrective means calculated based on the second objective eye refractive power. The initial correction value of the corrective means may also be the value of the second objective eye refractive power, or a correction value calculated based on the second objective eye refractive power. For example, the examiner may input information based on the second objective eye refractive power, acquired by at least one of the display control means, print control means, etc., by operating the operating means. The corrective control means may set the initial correction value of the corrective means based on the operation signal from the operating means.

<Response Input Method>
The optometry device of this embodiment may include a response input means. The response input means is a means for the subject to input their response to interpreting the test target. For example, the response input means may be an operating means such as a lever switch or a push-button switch (for example, a subject controller 220). The response input means may be provided integrally with the housing of the optometry device. Alternatively, the response input means may be provided separately from the housing of the optometry device.

The response input means may be configured to allow input in multiple predetermined directions. For example, it may allow input in four directions: up, down, left, and right. In other words, it may allow input of angles of 0° (360°), 90°, 180°, and 270°. Of course, it may allow input in more than four directions, or it may allow input in all directions from 0° to 359°.

<Control means>
The optometry device of this embodiment may include control means. After the initial correction value of the correction means is set by the correction control means, the control means automatically proceeds with the subjective measurement based on the input signal from the response input means. More specifically, after changing the refractive power for correcting the eye under examination based on the initial correction value of the correction means, the control means automatically proceeds with the subjective measurement based on the input signal from the response input means. For example, a self-examination program may be run to allow the subject to perform a so-called self-examination, in which the subject performs the subjective measurement themselves. In self-examination, it is not easy to match the second distance of the subjective measurement with the first distance of the objective measurement, so there is a high possibility that the eye will be corrected with different refractive powers at the start of the subjective measurement. However, as in this embodiment, when the first distance and the second distance are different, the first objective refractive power based on the first distance is converted to the second objective refractive power based on the second distance and output, thereby correcting the eye under examination with a predetermined refractive power and enabling smooth subjective measurement.

The optometry device of this embodiment may be an objective optometry device that objectively measures the refractive power of the eye being examined. In an objective optometry device, it is also possible to convert the first objective refractive power based on a first distance to a second objective refractive power based on a second distance and output it. In this case, the optometry device may include: an objective refractive power acquisition means for acquiring the objective refractive power of the eye being examined in an objective measurement; a first distance acquisition means for acquiring the first distance from the corneal apex of the eye being examined to the lens fitting reference position in an objective measurement; a second distance acquisition means for acquiring the second distance from the corneal apex of the eye being examined to the lens fitting reference position in a subjective measurement; a conversion means for converting the first objective refractive power based on the first distance to the second objective refractive power based on the second distance when the first and second distances are different; and an output means for outputting the second objective refractive power.

This disclosure is not limited to the apparatus described in this embodiment. For example, terminal control software (program) performing the functions of the above embodiment can be supplied to a system or apparatus via a network or various storage media, and the control device (e.g., CPU) of the system or apparatus can read and execute the program.

<Examples>
The following describes examples of the ophthalmic device relating to this disclosure. The items classified in <> below may be used independently or in relation to each other.

<Device configuration>
Figure 1 is a perspective view showing the entire subjective optometry device 1 from the front. For example, in this embodiment, the side where the eye to be examined E is located is described as the front of the entire subjective optometry device, and the side where the examiner's eye OE is located is described as the back of the entire subjective optometry device.

For example, the subjective optometry device 1 includes a support arm 2, an optometry table 3, a controller 71, a refractive power measurement unit 50, a target presentation unit 60, etc. For example, the eye being examined E observes the test target from the front of the refractive power measurement unit 50 through the examination window 53 (described later). For example, the examiner's eye OE observes the front of the eye being examined E from the rear of the refractive power measurement unit 50 through the examination window 53 (described later). Also, for example, the examiner's eye OE observes the side of the eye being examined E from the rear of the refractive power measurement unit 50 through the confirmation window 11 (described later).

<Eye Refractive Power Measurement Unit>
The refractive power measurement unit 50 will now be described. Figure 2(a) is a schematic view of the refractive power measurement unit 50 according to this embodiment, shown from the front (the eye being examined, side E). Figure 2(b) is a schematic view of the refractive power measurement unit 50 according to this embodiment, shown from the rear (the examiner's eye, side E). For example, the refractive power measurement unit 50 includes a forehead rest 51, a connecting part 52, a forehead rest adjustment knob 5, an examination window 53, a moving unit 54, a pair of left and right lens chamber units 55, etc.

For example, the forehead rest 51 fixes the position of the subject's face by contacting the subject's forehead. Therefore, the subject's eye E is kept at a constant distance from the examination window 53. For example, the connecting part 52 has one end connected to the forehead rest 51 and the other end connected to the moving unit 54. For example, the forehead rest adjustment knob 5 is used to adjust the position of the forehead rest 51.

For example, the moving unit 54 includes a drive unit 58, a drive unit 59, etc. For instance, the drive unit 58 has a sliding mechanism to adjust the spacing of the lens chamber units 55. This allows the examiner to change the spacing of the examination windows 53 to match the interpupillary distance of the eye E being examined. Furthermore, for example, the drive unit 59 has a convergence mechanism to adjust the convergence angle (collision angle) of the lens chamber units 55. For detailed information on the configuration of the moving unit, please refer to Japanese Patent Application Publication No. 2004-329345.

For example, the lens chamber unit 55 includes a light source 40, a lens disk 45, a drive unit 56, a drive unit 57, a corneal position aiming unit 10, a suppression unit 30, etc. For example, an LED (Light-emitting diode) is used for the light source 40. For example, the light source 40 includes a first light source 40a that illuminates one of the left or right eyes being examined, and a second light source 40b that illuminates the other eye being examined (see Figures 2(a) and 3). For example, in this embodiment, the first light source 40a is positioned in the left eye lens chamber unit 55L to illuminate the left eye EL, and the second light source 40b is positioned in the right eye lens chamber unit 55R to illuminate the right eye ER.

For example, the lens disc 45 has numerous optical elements 46 (spherical lenses, cylindrical lenses, dispersion prisms, etc.) arranged on the same circumference. For example, the drive unit 56 (actuator, stepping motor, etc.) controls the rotation of the lens disc 45. This allows the optical elements 46 desired by the examiner to be switched and positioned in the inspection window 53. For example, the drive unit 57 (motor, solenoid, stepping motor, etc.) controls the rotation of the optical elements 46 positioned in the inspection window 53. This allows the optical elements 46 to be positioned in the left and right inspection windows 53 at the rotation angle desired by the examiner.

For example, the lens disk 45 consists of one lens disk or multiple lens disks. For example, if multiple lens disks (a group of lens disks) are provided, a drive unit corresponding to each lens disk is provided. For example, each lens disk in a group of lens disks includes an aperture (or a 0D lens) and multiple optical elements. Typical types of lens disks include a spherical lens disk having multiple spherical lenses of different powers, a cylindrical lens disk having multiple cylindrical lenses of different powers, and an auxiliary lens disk. For example, an auxiliary lens disk may contain at least one of the following: a red filter/green filter, a prism, a cross-cylinder lens, a polarizer, a Maddox lens, or an auto-cross-cylinder lens. For detailed information on the lens disk configuration, please refer to Japanese Patent Publication No. 2007-68574 and Japanese Patent Publication No. 2011-72431.

<Corneal position aiming unit>
The corneal position aiming unit 10 will now be described. Figure 3 shows the corneal position aiming unit 10. For example, the corneal position aiming unit 10 comprises a first corneal position aiming unit 10a and a second corneal position aiming unit 10b. For example, in this embodiment, a configuration is given in which the left eye lens chamber unit 55L has the first corneal position aiming unit 10a and the right eye lens chamber unit 55R has the second corneal position aiming unit 10b.

For example, the first corneal position aiming unit 10a is used to confirm the distance between the corneal vertex of one eye under examination (e.g., the left eye EL in this embodiment), illuminated by the first light source 40a, and the lens mounting reference position (described later). For example, the first corneal position aiming unit 10a consists of a first confirmation window 11a, a first observation window 12a, and a first corneal position aiming optical system 20a. For example, the first confirmation window 11a is used to confirm the first corneal position aiming optical system 20a, located inside the eye refractive power measurement unit 50, from outside the eye refractive power measurement unit 50. For example, the first observation window 12a is used to guide the reflected light, illuminated from the first light source 40a and reflected by one eye under examination (e.g., the left eye EL), to the first corneal position aiming optical system 20a located inside the eye refractive power measurement unit 50.

For example, the first corneal position aiming optical system 20a guides the reflected light, illuminated from the first light source 40a and reflected by one of the eyes under examination (e.g., the left eye EL), to the first confirmation window 11a. For example, the first corneal position aiming optical system 20a includes a reflective mirror 22, an aiming scale plate 23, a reticle plate 24, etc. For example, the reflective mirror 22 is positioned laterally (in the X direction) of the left eye EL. For example, the aiming scale plate 23 is provided between the reflective mirror 22 and the first confirmation window 11a. Alternatively, the aiming scale plate 23 may be provided between the left eye EL and the reflective mirror 22. For example, the reticle plate 24 is positioned on the back side of the first confirmation window 11a (inside the left eye lens chamber unit 55L).

For example, Figure 4 is a diagram showing the configuration of the aiming scale plate 23 and the reticle plate 24. Figure 4(a) shows the aiming scale plate 23, and Figure 4(b) shows the reticle plate 24. For example, the aiming scale plate 23 has several scale lines N1 to N5, a center line N6, and a first indicator 27. For example, the scale lines N1 to N5 correspond to corneal vertex distances (see Figure 3) of 12 mm, 13.75 mm, 16 mm, 18 mm, and 20 mm, respectively. For example, scale line N2 (13.75 mm) is the reference position when the lens is fitted and is drawn to distinguish it from the other scale lines. For example, the center line N6 is used as a reference for aligning the reticle 28 on the reticle plate 24. Also, for example, the center line N6 is located in the left-right center of the aiming scale plate 23. For example, the reticle plate 24 is equipped with a reticle 28 and a second indicator 29, etc. For instance, the reticle 28 is triangular in shape. Furthermore, the reticle 28 is located in the center of the left-right position of the reticle plate 24. For example, a numerical value 25 indicating the corneal vertex distance is displayed on the outer periphery of the reticle plate 24.

For example, the first indicator 27 on the aiming scale plate 23 and the second indicator 29 on the reticle plate 24 are indicators for guiding the examiner's eye OE to a predetermined distance from the reticle plate 24. For example, in this embodiment, when the examiner's eye OE is located 250 mm away from the reticle plate 24, the first indicator 27 and the second indicator 29 appear to overlap. For example, when the first indicator 27 is positioned inward relative to the second indicator 29, the examiner's eye OE is located closer than 250 mm from the reticle plate 24. Conversely, when the first indicator 27 is positioned outward relative to the second indicator 29, the examiner's eye OE is located further than 250 mm from the reticle plate 24. For detailed information on the configuration of the aiming scale plate and the reticle plate and their respective positional relationships, please refer to Japanese Patent Application Publication No. 2004-229769.

For example, the second corneal position aiming unit 10b is used to confirm the distance between the corneal apex of the other eye under examination (e.g., the right eye ER in this embodiment), which is illuminated by the second light source 40b, and the lens fitting reference position. For example, the second corneal position aiming unit 10b consists of a second confirmation window 11b, a second observation window 12b, and a second corneal position aiming optical system 20b. For example, the second confirmation window 11b is used to confirm the second corneal position aiming optical system 20b, which is located inside the eye refractive power measurement unit, from outside the eye refractive power measurement unit 50. Also, for example, the second observation window 12b is used to guide the reflected light, illuminated from the second light source 40b and reflected by one of the eyes under examination (e.g., the left eye EL), to the second corneal position aiming optical system 20b located inside the eye refractive power measurement unit 50.

For example, the second corneal position aiming optical system 20b guides the reflected light, illuminated from the second light source 40b and reflected by the other eye under examination (e.g., the right eye ER), to the second confirmation window 11b. Since the configuration of the second corneal position aiming optical system 20b is the same as that of the first corneal position aiming optical system 20a, its description is omitted in this embodiment. Of course, some parts of the configuration of these corneal position aiming optical systems may differ.

<Optotype presentation part>
The target presentation unit 60 presents the test target to the eye E under examination. For example, the target presentation unit 60 may be a display, a light source and a DMD, a light source and a target board, etc. In this embodiment, a display 61 is used as the target presentation unit 60. For example, the display 61 may be an LCD (Liquid Crystal Display), an organic EL (Electro Luminescence), a plasma display, etc.

The display 61 is positioned at a predetermined distance from the refractive power measurement unit 50. For example, it is positioned at a distance corresponding to the distance distance required for distance vision testing of the eye E being examined (e.g., 5 m). The display 61 is connected to the controller 71 wirelessly or via a wired connection, and displays the test target in response to the operation signals input from the controller 71.

<Controller>
For example, the controller 71 is used to input the subject's objective values (e.g., spherical refractive power, cylindrical refractive power, astigmatism axis angle, etc.) and interpupillary distance, and to switch the arrangement of the optical elements 46 and the examination window 53 in the ocular refractive power measurement unit 50. Also, for example, the controller 71 is used to switch the test target presented to the eye E under examination. For example, the controller 71 is not fixed to the eye examination table 3, but can be carried around by the examiner at will.

For example, the controller 71 includes a display unit 72. For instance, the display unit 72 displays information about the optical elements located in the refractive power measurement unit 50, the subject's refractive power information acquired from other devices, and so on. For example, operation signals input from the controller 71 are input to the control unit 70 via a cable. Alternatively, the operation signals from the controller 71 may be input to the control unit 70 via wireless communication such as infrared.

<Control Unit>
For example, Figure 5 is a schematic diagram of the control system in the subjective optometry device 1. For example, the control unit 70 is electrically connected to the controller 71, non-volatile memory 73, first light source 40a, second light source 40b, the drive units (drive units 56, 57, 58, 59) of the ocular refractive power measurement unit 50, the target presentation unit 60 (display 61), and the like.

For example, the control unit 70 includes a CPU (processor), RAM, ROM, etc. For example, the CPU controls the various components of the subjective optometry device 1. For example, RAM temporarily stores various types of information. For example, ROM stores various programs for controlling the operation of the subjective optometry device 1. Note that the control unit 70 may be composed of multiple control units (i.e., multiple processors).

For example, non-volatile memory 73 is a non-transient storage medium that can retain its contents even when the power supply is interrupted. For example, a hard disk drive, flash ROM, USB memory, etc., can be used as the non-volatile memory 73.

<Control operation>
The operation of the subjective ophthalmography device having the above configuration will now be explained.

The procedure for subjective measurement using the subjective optometry device of this embodiment will be explained following the flowchart in Figure 6. For example, first, with the left eye corrected to a predetermined correction power (initial correction value) based on objective refractive power (objective value), subjective measurement of the left eye is performed, and the subjective refractive power (subjective value) of the left eye is obtained. After the measurement of the left eye is completed, the measurement of the right eye is performed in the same manner, and the subjective value of the right eye is obtained.

<Acquisition of objective values using a subjective ophthalmoscopic device (S1)>
In step S1, a first objective value is acquired to initiate subjective measurement of the eye under examination. The examiner retrieves the first objective value of the eye under examination, which was previously measured using the objective eye refractive power measuring device 100 (see Figure 7), and receives it into the subjective eye examination device. For example, the first objective value is stored in a memory (not shown) of the objective eye refractive power measuring device 100, associated with the subject's ID. For details on objective measurement using the objective eye refractive power measuring device, please refer to, for example, Japanese Patent Application Publication No. 2005-185523.

Figure 7 shows a configuration diagram of an objective eye power measurement device and a subjective eye examination device. For example, in this embodiment, the objective eye power measurement device 100 and the subjective eye examination device 1 are wirelessly connected. This enables data transmission and reception between the objective eye power measurement device 100 and the subjective eye examination device 1. Of course, these devices may be connected by wire instead of wirelessly.

For example, the examiner operates the controller 71 of the subjective optometry device 1 and inputs the subject's ID. The control unit 70 of the subjective optometry device 1 outputs an operation signal to the objective refractive power measuring device 100, causing it to transmit the first objective value associated with the subject's ID. The control unit (not shown) of the objective refractive power measuring device 100, upon receiving the subject's ID from the subjective optometry device 1, retrieves the first objective value corresponding to the subject's ID from memory and transmits it to the subjective optometry device 1. The control unit 70 of the subjective optometry device 1 receives the first objective value transmitted from the objective refractive power measuring device 100. This allows the control unit 70 to obtain the first objective value of the eye being examined.

<Acquisition of the first distance in a subjective optometry device (S2)>
In step S2, the corneal vertex distance V1 (hereinafter referred to as the first distance V1) of the eye E under examination is obtained in an objective measurement. For example, the first distance V1 in the objective measurement is the distance from the corneal vertex of the eye E under examination to the position where the spectacle lens is assumed to be positioned when the eye under examination is fitted with spectacle lenses (lens fitting reference position). Details of the first distance V1 will be described later. In the objective measurement, the first distance V1 is set in advance as a predetermined distance, and the first objective value based on the first distance V1 is obtained. For example, in this embodiment, the first distance V1 is set to 12 mm, and assuming that the spectacle lens is placed 12 mm away from the eye E under examination, the refractive power that corrects the eye E to 0D (for example, spherical power, cylindrical power, and astigmatism axis angle, etc.) is obtained as the first objective value based on the first distance V1.

In this objective measurement of the eye E under examination, the first distance V1 is obtained based on data transmission between the objective refractive power measuring device 100 and the subjective optometry device 1. For example, the first distance V1, along with the first objective value obtained in step S1, is transmitted from the control unit of the objective refractive power measuring device 100 to the control unit 70 of the subjective optometry device 1. This allows the control unit 70 to acquire the first distance V1.

<Acquisition of the second distance in a subjective optometry device (S3)>
In step S3, the corneal vertex distance V2 (hereinafter referred to as the second distance V2) in the subjective measurement is obtained. For example, the second distance V2 in the subjective measurement is the distance from the position of the corneal vertex of the eye under examination E to the position where the spectacle lens will be positioned when the eye under examination is fitted with spectacle lenses (lens fitting reference position). Details of the second distance V2 will be described later. In the subjective measurement, the second distance V2 is obtained by measuring the second distance V2 using the corneal position aiming unit 10.

First, the examiner instructs the subject to look into the examination window 53. The subject, in accordance with the examiner's instructions, places their face against the forehead rest 51 on the refractive power measurement unit 50 and looks into the examination window 53. At this point, the examiner operates the controller 71 to set a mode for observing the position of the subject's corneal apex, and the control unit 70 illuminates the first light source 40a and the second light source 40b, respectively. This illuminates the left eye EL and the right eye ER with sufficient light intensity.

Next, the examiner looks through the first confirmation window 11a of the left eye lens chamber unit 55L to confirm the position of the corneal apex of the left eye EL. Figure 8 shows the aiming scale plate 23 and reticle plate 24 when confirming the position of the corneal apex. The examiner searches for the position where the first indicator 27 on the aiming scale plate 23 and the second indicator 29 on the reticle plate 24 align vertically and horizontally, so that the first and second indicators overlap and appear as one. Furthermore, the examiner searches for the position where the tip of the reticle 28 and the center line N6 appear to align.

For example, as described above, the examiner adjusts the position of the forehead rest 51 on the refractive power measurement unit 50 by operating the forehead rest adjustment knob 5 (see Figure 2(b)) while checking the lateral position of the left eye EL using the first confirmation window 11a. This allows the position of the corneal apex of the left eye EL to be moved. For example, if the corneal apex of the left eye was located around the scale line N2 but slightly off from it, the forehead rest adjustment knob 5 can be used to align the corneal apex with the scale line N2. After this, the examiner similarly adjusts the position of the corneal apex of the right eye ER using the second confirmation window 11b to align the corneal apex with the scale line N2. Note that the positions of the corneal apex of the left eye EL and the right eye ER can be adjusted from either side.

In this embodiment, since the position of the corneal apex of the eye under examination E coincides with the scale line N2, the second distance V2 for eye under examination E is 13.75 mm. For example, the examiner reads the numerical value 25 indicating the corneal apex distance based on the scale line N2 and inputs the second distance V2 using the controller 71. This allows the control unit 70 to acquire the second distance V2.

<Conversion of initial values in subjective measurement (S4)>
The control unit 70 starts subjective measurement of the eye E by adding a predetermined correction power (i.e., an initial value) to the eye E so that the eye E is corrected to a predetermined refractive power based on the first objective value. For example, a predetermined initial value is added to the eye E so that the target light beam from the display 61 is focused on the retina via the optical element 46 (in other words, so that the refractive power of the eye E becomes 0D). As an example, if the objective value of the eye E is a spherical power of -2.0D, a cylindrical power of -1.0D, and an astigmatism axis angle of 45 degrees, adding these powers and angles as initial values will result in a refractive power of 0D.

In step S4, the initial values used when starting this subjective measurement are converted as needed. In this embodiment, the control unit 70 sets the initial values for the subjective measurement based on the first objective value and first distance V1 from the objective measurement of the eye E under examination, and the second distance V2 from the subjective measurement. This will be explained in detail below.

Figure 9 is a schematic diagram of the first distance in objective measurement and the second distance in subjective measurement. Figure 9(a) shows the first distance. Figure 9(b) shows the second distance. For example, the first distance V1 in the objective eye refractive power measuring device 100 is, as described above, the distance from the position of the corneal apex 82 of the eye under examination E to the lens mounting reference position where the spectacle lens 80 is placed when the eye under examination wears spectacle lenses. More specifically, it is the distance from the position of the corneal apex 82 of the eye under examination to the position 81 of the back surface of the spectacle lens 80. For example, the second distance V2 in the subjective eye examination device 1 is, as described above, the distance from the position of the corneal apex 82 of the eye under examination E to the lens mounting reference position. In this embodiment, the eye refractive power measuring unit 50 is located in front of the eye under examination E, and the examination window 53 and multiple lens discs 45 are arranged in the order of moving away from the eye under examination E. For example, among the multiple lens discs 45, the optical element 46a of the lens disc 45 closest to the eye being examined E is positioned following the examination window 53. In the subjective optometry device 1, the second distance V2 can be considered as the distance from the position of the corneal apex 82 of the eye being examined to the position of the posterior surface of the optical element 46a.

Here, if the first objective measurement distance V1 and the second subjective measurement distance V2 differ, the refractive power of the eye being examined may not be corrected to 0D even if an initial value based on the first objective value of the eye being examined is added.

For example, in Figure 9(a), the vertex-to-vertex distance of the corneal eye E is the first distance V1, and the target light beam directed towards the eye E is refracted by the spectacle lens 80, the cornea, and the lens, and focuses at the focal point f1 on the retina. In other words, the refractive power of the eye E is corrected to 0D. On the other hand, for example, as in Figure 9(b), if the vertex-to-vertex distance of the corneal eye E is the second distance V2, which is longer than the first distance V1, the target light beam directed towards the eye E is refracted by the optical element 46a located in front of the spectacle lens 80, the cornea, and the lens, and focuses at the focal point f2 behind the retina. Note that if the spectacle lens 80 and the optical element 46a are negative lenses, the longer the second distance V2 is relative to the first distance V1, the further behind the retina the target light beam will be located. Although not shown in the diagram, the shorter the second distance V2 is relative to the first distance V1, the closer the target light beam will be positioned in front of the retina.

Therefore, if the first objective value of the eye being examined is set as the initial value for subjective measurement, and there is a discrepancy V3 between the first distance V1 and the second distance V2, a discrepancy 84 will occur between the focusing position f1 and the focusing position f2. As a result, the actual refractive power of the eye when the eye is viewed through the refractive power measurement unit 50 to the display 61 will be corrected to a value different from 0D. For example, even if the first objective value of the eye being examined is a spherical power of -2.0 and a spherical lens of -2.0D is placed as the optical element 46, the eye will be in the same state as if it were viewing the test target through a spherical lens weaker than -2.0D (e.g., -1.75D).

Therefore, in this embodiment, if the first objective measurement distance V1 and the second subjective measurement distance V2 are the same, the first objective value of the objective measurement is set as the initial value of the subjective measurement. Furthermore, if the first objective measurement distance V1 and the second subjective measurement distance V2 are different, the first objective value of the objective measurement is converted (corrected) based on the first and second distances V2 to obtain a second objective value, and this second objective value is set as the initial value of the subjective measurement.

In this embodiment, the first objective value of the eye under examination is converted based on the difference between the first distance V1 and the second distance V2. For example, a correction amount is determined to convert the first objective value based on the first distance V1 to the second objective value based on the second distance V2 by using a lookup table that associates the first objective value of the eye under examination with the difference between the first distance V1 and the second distance V2. As an example, the lookup table is configured to determine the correction amount to be added to the first objective value by referring to the first objective value of the eye under examination and the difference between the first distance V1 and the second distance V2.

For example, the lookup table may be pre-set based on experimental or simulation results. One example is to pre-set the refractive power corresponding to the shift 84 in the focal point position of the target light beam, which changes due to differences between the first distance V1 and the second distance V2, by determining this refractive power through experiments or simulations, and obtaining it as a correction amount. The lookup table may be provided for each spherical power, cylindrical power, and astigmatism axis angle, and is stored in the non-volatile memory 73.

For example, the control unit 70 retrieves a lookup table from the non-volatile memory 73 and references the first objective value of the eye under examination and the amount of deviation between the first distance V1 and the second distance V2. In this embodiment, since the first distance V1 is 12 mm and the second distance V2 is 13.75 mm, the amount of deviation is 1.75 mm. Based on this, the control unit 70 can obtain a correction amount corresponding to the 1.75 mm deviation for converting the first objective value to the second objective value, and can also obtain the second objective value by adding the correction amount to the first objective value.

<Measurement of subjective perception (S5)>
In step S5, the second objective value obtained in step S4 is set as the initial value, and subjective measurement of the eye under examination is started. For example, the control unit 70 controls the rotation angle of the lens disk 45 and the rotation angle of the optical element 46 to correct the eye under examination E with the second objective value. For example, the rotation angle of the lens disk 45 is changed to position the optical element 46 with the spherical power and cylindrical power of the second objective value in the eye examination window 53. Alternatively, the rotation angle of the optical element 46 with the cylindrical power of the second objective value is changed to position it in the eye examination window 132 with the astigmatic axis angle of the second objective value. This allows the second objective value to be added to the eye under examination E. As a result, even if the first objective measurement distance V1 and the second subjective measurement distance V2 are different, the difference 84 in focal positions (f1 and f2) (see Figure 9(b)) is corrected, and the target light beam incident on the eye under examination is focused onto the retina via the optical element 46 (the refractive power of the eye under examination is corrected to 0D).

The examiner conducts a subjective measurement of the subject's visual acuity at the distance of the eye E, while changing the test target presented to the eye E and the corrective power applied to the eye. For example, the examiner operates the controller 71 to select a desired test target. The control unit 70 retrieves the corresponding test target data from the non-volatile memory 73 in response to the input signal from the controller 71 and displays it on the display 61. The test target displayed on the display 61 is presented to the subject's eye E via the test window 53 and optical element 46 of the refractive power measurement unit 50. For example, the examiner switches the test targets and asks the subject how well they can see them. For example, if the subject's answer is correct, the examiner switches to a target with a higher visual acuity value. For example, if the subject's answer is incorrect, the examiner switches to a target with a lower visual acuity value. Furthermore, for example, the examiner conducts the examination while simultaneously changing the corrective power of the eye being examined (E) as they switch the test target.

<Acquisition of subjective perception (S6)>
In step S6, subjective values of the eye being examined E are acquired. For example, the control unit 70 stores the measurement results, such as spherical power, cylindrical power, and astigmatism axis angle, as subjective values of the eye being examined E in the non-volatile memory 73. The control unit 70 also displays the subjective values of the eye being examined E on the display unit 72 of the controller 71.

As explained above, for example, the optometry device of this embodiment includes: an objective refractive power acquisition means for acquiring the objective refractive power of the eye under examination in an objective measurement; a first distance acquisition means for acquiring the first distance from the corneal apex of the eye under examination to the lens fitting reference position in an objective measurement; a second distance acquisition means for acquiring the second distance from the corneal apex of the eye under examination to the lens fitting reference position in a subjective measurement; a conversion means for converting the first objective refractive power based on the first distance to the second objective refractive power based on the second distance when the first and second distances are different; and an output means for outputting the second objective refractive power. For example, when the first and second distances are different, the focusing position of the target light beam incident on the eye under examination may shift, and the eye may actually be corrected with a different refractive power at the start of the subjective measurement of the eye under examination. However, by outputting a second objective refractive power that takes into account this shift in the light-gathering position, the eye being examined can be correctly corrected to a predetermined refractive power (for example, 0D), allowing for smooth subjective measurement.

Furthermore, for example, the optometry device in this embodiment sets the initial correction value of the correction means based on the second objective refractive power obtained by converting the first objective refractive power. This allows the eye to be easily corrected to a predetermined refractive power at the start of subjective measurement of the eye, thereby suppressing the shift in the focusing position of the target light beam incident on the eye, and enabling smooth subjective measurement.

<Examples of transformation>
In this embodiment, when acquiring the second distance V2 in the subjective measurement of the eye E under examination, the position of the corneal apex 82 of the eye E under examination is finely adjusted to match the scale line N2 closest to the corneal apex 82, and the numerical value 25 is read and input. However, the embodiment is not limited to this. For example, a scale line for positioning the corneal apex 82 of the eye E under examination may be predetermined, and the numerical value 25 corresponding to this scale line may be set in advance as the second distance V2. In other words, the second distance V2 may be set in advance as a fixed distance. This eliminates the need for the examiner to input the second distance V2 into the device. In this case, the examiner can adjust the second distance V2 by operating the forehead adjustment knob 5 (see Figure 2(b)) so that the position of the corneal apex 82 of the eye E under examination coincides with a predetermined scale line.

Furthermore, in this embodiment, we have explained, as an example, how to determine a correction amount for converting the first objective value based on the first distance V1 to the second objective value based on the second distance V2, using a lookup table that associates the first objective value of the eye under examination with the amount of deviation between the first distance V1 and the second distance V2. However, we are not limited to this. For example, a predetermined calculation formula that can calculate the correction amount based on the first objective value of the eye under examination and the amount of deviation between the first distance V1 and the second distance V2 may be used.

Furthermore, while this embodiment describes setting the second objective value, obtained by adding a correction amount to the first objective value of the eye E under examination, as the initial value for subjective measurement, it is not limited to this. For example, it may be possible to select whether to set the first objective value or the second objective value of the eye E under examination as the initial value for subjective measurement. In this case, the control unit 70 may display the first objective value obtained by objective measurement and the second objective value, obtained by adding a correction amount to the first objective value, on the display unit 72 of the controller 71. The control unit 70 may also set a value corresponding to the operation signal based on the examiner's selection as the initial value and switch the arrangement of the optical elements accordingly.

In this embodiment, when the first objective measurement distance V1 and the second subjective measurement distance V2 are different, the initial value for starting the subjective measurement is set based on the second objective value obtained by converting the first objective value of the objective measurement. However, the embodiment is not limited to this. For example, the control unit 70 may convert the first objective value to the second objective value and set the initial value based on the second objective value when the first distance V1 and the second subjective measurement distance V2 are different and the first objective value exceeds a predetermined threshold. For example, the first objective value may be converted to the second objective value when the spherical frequency S in the first objective value exceeds a predetermined threshold. Also, for example, the first objective value may be converted to the second objective value when the cylindrical frequency C in the first objective value exceeds a predetermined threshold. Also, for example, the first objective value may be converted to the second objective value when the astigmatism axis angle A in the first objective value exceeds a predetermined threshold. In this embodiment, the first objective value may be converted to the second objective value if the spherical frequency S exceeds a predetermined threshold.

For example, in this embodiment, the optometry device converts the first objective refractive power (based on the first distance) to the second objective refractive power (based on the second distance) when the first objective refractive power differs from the second objective refractive power (based on the second distance) when the first objective refractive power exceeds a predetermined threshold. For instance, the larger the absolute value of the first objective refractive power (i.e., the higher the degree of refractive power), the greater the change in actual refractive power caused by the difference between the first objective and second objective refractive powers. Therefore, in situations where the difference between the first and second distances has a greater impact, converting the first objective refractive power to the second objective refractive power and outputting it allows for correct correction of the eye to the predetermined refractive power.

In this embodiment, the case in which the examiner reads the second distance V2 using the aiming scale plate 23 and the reticle plate 24 was described as an example, but the embodiment is not limited to this. For example, the refractive power measurement unit 50 may be provided with a detection unit for detecting the second distance V2, so that the second distance V2 can be acquired automatically. In this embodiment, the case in which an image sensor is used as such a detection unit is given as an example.

Figure 10 shows the arrangement of image sensors in the corneal position aiming unit. For example, the image sensor 13 for detecting the second distance V2 is positioned behind the first confirmation window 11a and the second confirmation window 11b, respectively. As a result, reflected light emitted from the first light source 40a and reflected from the eye under examination E is captured by the image sensor 13 via the first observation windows 12a, 20a, 23, 24, and 11a. Similarly, reflected light emitted from the second light source 40b and reflected from the eye under examination E is captured by the image sensor 13 via the second observation windows 12b, 20, 23, 24, and 11b. This allows for the acquisition of an image including the corneal apex 82 of the eye under examination E, the aiming scale plate 23, and the reticle plate 24.

The control unit 70 detects the corneal vertex 82 of the eye under examination E and the scale lines (N1 to N5) of the aiming scale plate 23 by analyzing the captured image. For example, edge detection using brightness values may be used as the detection method for the corneal vertex 82 and scale lines of the left eye EL. The control unit 70 also detects the scale line to which the corneal vertex 82 of the eye under examination E touches. For example, the distance between corneal vertices is associated with each scale line, and a second distance V2 can be obtained based on the scale lines. Similarly, for the right eye ER, the image analysis process can be performed to obtain the second distance V2. Note that the image sensor 13 only needs to be positioned in a location where the second distance V2 can be detected, and is not limited to this embodiment.

For example, as described above, the optometry device of this embodiment detects the second distance in the subjective measurement of the eye under examination and obtains the second distance based on the detection result. This makes it easy to determine whether the second distance in the subjective measurement matches the first distance in the objective measurement. As a result, the eye under examination can be corrected with an appropriate refractive power based on either the first or second objective refractive power.

In this embodiment, the configuration described as acquiring the position of the corneal apex 82 of the eye under examination at the start of the subjective measurement of the eye under examination E is used as an example, but the system is not limited to this. For example, the configuration may also acquire the position of the corneal apex 82 during the subjective measurement of the eye under examination E. For example, the control unit 70 may acquire the image captured by the image sensor 13 in real time and notify the system when the position of the corneal apex 82 changes (in other words, when the second distance V2 changes) using a notification unit (not shown). For example, an acceptable range may be provided for detecting whether or not the position of the corneal apex 82 has changed. For example, the notification unit may be at least one of a speaker, buzzer, display, etc. This allows for accurate subjective measurement of the eye under examination E.

Furthermore, the conversion of the initial value at the start of subjective measurement in this embodiment can also be applied to a space-saving subjective optometry device (see, for example, Japanese Patent Application Publication No. 2019-000346) that has a target presentation unit for presenting the test target to the eye E within its housing, and guides the target light beam from the target presentation unit to the outside of the housing by reflecting it with an optical member, and this target light beam reaches the eye via the refractive power measurement unit 50.

Furthermore, the conversion of initial values at the start of subjective measurement in this embodiment can be applied to so-called self-examinations, where the examiner is not present and the subject performs the subjective measurement themselves. For example, in this case, a subject-user controller for inputting answers may be provided in the subjective optometry device 1 shown in Figure 1, or a subject-user controller may be provided in a space-saving subjective optometry device. The following explanation of such self-examinations will use a space-saving subjective optometry device as an example.

Figure 11 is an external view of a space-saving subjective optometry device 200. Figure 11(a) is a perspective view of the external appearance of the subjective optometry device 200. Figure 11(b) is an internal side view of the subjective optometry device 200. For example, the subjective optometry device 200 includes a housing 201, a display window 202, a speaker 203, a holding unit 204, an examiner controller 210, a subject controller 220, an ocular refractive power measurement unit 240, etc. The ocular refractive power measurement unit 240 has the same configuration as the ocular refractive power measurement unit 50 described above, and its explanation is omitted here.

The housing 201 contains the light projection optical system 230. The display window 202 transmits the target light beam from the light projection optical system 230. The speaker 203 outputs audio guidance, etc. The holding unit 204 holds the eye refractive power measurement unit 240.

The examiner controller 210 is used by the examiner to operate the subjective ophthalmoscopic examination device 200. The examiner controller 210 includes a switch unit 211, a monitor 212, etc. The switch unit 211 receives signals for various settings (e.g., movement of the refractive power measurement unit 240, etc.). The monitor 212 displays various information (e.g., measurement results of the eye being examined E, etc.). The monitor 212 may also function as a touch panel that doubles as the switch unit 211. Signals from the examiner controller 210 are output to a control unit (not shown) via wired or wireless communication.

The subject controller 220 is used to input the subject's responses. The subject controller 220 includes a response lever 221, response buttons 222, etc. The response lever 220 is used when the subject inputs the direction relative to the test target. For example, signals for the four directions (up, down, left, and right) can be input by tilting. The response buttons 222 are used when the subject does not select a direction relative to the test target. Signals from the subject controller 220 are output to a control unit (not shown) via wired or wireless communication.

The light projection optical system 230 (see Figure 11(b)) projects a target light beam toward the eye E under examination. For example, the light projection optical system 230 includes a display 231, a planar mirror 232, a concave mirror 233, etc. The target light beam emitted from the display 231 is guided out of the housing 201 via the planar mirror 232, the concave mirror 233, and the planar mirror 232 in that order, and is then projected onto the eye E under examination via the presentation window 202 and the examination window and optical elements of the refractive power measurement unit 240.

In such a subjective optometry device 200, initial values are set based on the first objective value of the eye being examined E so that the eye E has a predetermined refractive power (e.g., 0D), and the subjective measurement proceeds automatically when the self-examination application is executed. For example, in self-examination, the subject can start the subjective measurement by placing their face against the forehead rest and then operating the subject controller 220. At this time, the examiner is not always present, and there is a high possibility that the second distance V2 for subjective measurement will differ from the first distance V1 for objective measurement. Therefore, especially in self-examination, discrepancies in the actual refractive power are likely to occur due to the mismatch between the first distance V1 and the second distance V2.

In this embodiment, the subjective optometry device 200 may also set the initial value for subjective measurement based on the first objective value and first distance V1 of the objective measurement of the eye E under examination, and the second distance V2 of the subjective measurement of the eye E under examination. For example, the control unit may acquire the second distance V2 by analyzing the captured image using the detection unit (image sensor) provided in the refractive power measurement unit 240. Furthermore, if the first distance V1 and the second distance V2 are different, the first objective value based on the first distance V1 may be converted to a second objective value based on the second distance V2, and this may be set as the initial value for subjective measurement.

As described above, the optometry device of this embodiment presents the test target to the eye being examined, sets the initial correction value of the correction means, and then automatically proceeds with subjective measurement based on the input signal from the response input means in which the subject interprets the test target. For example, in so-called self-optometry, where the subject performs the subjective measurement themselves, it is not easy to match the second distance in subjective measurement with the first distance in objective measurement. Therefore, the first and second distances may not match at the start of subjective measurement, and the measurement may proceed with the eye corrected with different refractive powers, potentially leading to an extended measurement time. However, as in this embodiment, when the first and second distances differ, the first objective refractive power based on the first distance is converted to the second objective refractive power based on the second distance and output. This allows the eye being examined to be correctly corrected with a predetermined refractive power, even in self-optometry, enabling smooth subjective measurement.

In this embodiment, a subjective optometry device that subjectively measures the refractive power of the eye under examination is described as an example of a configuration that converts a first objective value based on a first distance V1 to a second objective value based on a second distance V2. However, the embodiment is not limited to this configuration. For example, an objective optometry device that objectively measures the refractive power of the eye under examination may be configured to convert the first objective value to a second objective value. In this case, the objective optometry device may measure the first objective value at the first distance V1 and receive the second distance V2 from the subjective optometry device, thereby converting the first objective value to the second objective value.

1. Subjective eye examination device 11. Confirmation window 12. Observation window 30. Suppression unit 40. Light source 50. Refractive power measurement unit 51. Forehead rest 53. Examination window 55. Lens chamber unit 60. Target presentation unit 70. Control unit 100. Objective eye refractive power measurement device 200. Subjective eye examination device

Claims (6)

An optometry device comprising a target presentation means for emitting a target light beam toward the eye to be examined, and a corrective means for changing the optical properties of the target light beam, wherein the refractive power of the eye to be examined is measured subjectively,
An objective refractive power acquisition means for acquiring the objective refractive power of the eye being examined in an objective measurement,
A first distance acquisition means for acquiring a first distance from the corneal apex of the eye to the lens fitting reference position in the objective measurement of the eye under examination,
A second distance acquisition means for acquiring a second distance from the corneal apex of the eye to the lens fitting reference position in the subjective measurement of the eye under examination,
When the first distance and the second distance are different, a conversion means is provided to convert the first objective refractive power based on the first distance to the second objective refractive power based on the second distance.
The output means for outputting the second objectively observed refractive power,
An optometry device characterized by being equipped with the following features. In the eye examination device of claim 1,
An optometry device characterized by comprising a correction control means for setting an initial correction value for the correction means based on the second objective eye refractive power output from the output means. In the ophthalmoscopic device according to claim 1 or 2,
The optometry device is characterized in that the conversion means converts the first objective eye refractive power to the second objective eye refractive power when the first distance and the second distance are different and the first objective eye refractive power exceeds a predetermined threshold. In the eye examination device of claim 1 ,
The system includes a detection means for detecting the second distance in the subjective measurement of the eye under examination,
The eye examination device is characterized in that the second distance acquisition means acquires the second distance based on the detection result of the detection means. An eye examination program for use in an eye examination device that includes a target presentation means for emitting a target light beam toward the eye to be examined, and a corrective means for changing the optical properties of the target light beam, and which subjectively measures the refractive power of the eye to be examined,
By being executed by the processor of the aforementioned ophthalmic device,
An objective refractive power acquisition step is performed to acquire the objective refractive power of the eye being examined in an objective measurement,
A first distance acquisition step of acquiring a first distance from the corneal apex of the eye to the lens fitting reference position in the objective measurement of the eye to be examined,
A second distance acquisition step in which a second distance is obtained from the corneal apex of the eye to the lens fitting reference position in the subjective measurement of the eye to be examined,
When the first distance and the second distance are different, a conversion step is made to convert the first objective eye refractive power based on the first distance to the second objective eye refractive power based on the second distance,
The output step of outputting the second objective eye refractive power,
An eye examination program characterized by causing the eye examination device to perform the following. An optometry device for measuring the refractive power of the eye being examined,
An objective refractive power acquisition means for acquiring the objective refractive power of the eye being examined in an objective measurement,
A first distance acquisition means for acquiring a first distance from the corneal apex of the eye to the lens fitting reference position in the objective measurement of the eye under examination,
A second distance acquisition means for acquiring a second distance from the corneal apex of the eye to the lens fitting reference position in the subjective measurement of the eye under examination,
When the first distance and the second distance are different, a conversion means is provided to convert the first objective refractive power based on the first distance to the second objective refractive power based on the second distance.
The output means for outputting the second objectively observed refractive power,
An optometry device characterized by being equipped with the following features.