Subjective optometric device and subjective optometric program

Abstract

To provide a subjective optometric device and a subjective optometric program capable of correctly acquiring a measurement result of a subject eye.SOLUTION: The subjective optometric device has correction means arranged in the middle of an optical path of a light-emitting optical system projecting a visual target light flux toward a subject eye and varying the optical characteristic of the visual target light flux, and subjectively measures the optical characteristic of the subject eye. The subjective optometric device comprises: anterior eye image acquisition means for acquiring an anterior eye image of the subject eye during the subjective measurement; overcorrection detection means for detecting whether or not the subject eye is in an overcorrection state, based on the anterior eye image acquired by the anterior eye image acquisition means; and operation control means for controlling an operation for cancelling the overcorrection state of the subject eye, based on a detection result detected by the overcorrection detection means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a subjective optometry device and a subjective optometry program for subjectively measuring optical characteristics of a subject's eye. [Background technology]

[0002] There is known a subjective optometry device that subjectively measures the optical characteristics of a subject's eye. For example, a subjective optometry device projects a visual target light beam toward the subject's eye and switches the correction power for correcting the subject's eye, thereby subjectively measuring the optical characteristics of the subject's eye (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-086652 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in subjective measurement using a subjective optometry device, the subject's eye may be overcorrected. For example, the overcorrected state is a state in which a light beam incident on the subject's eye forms an image behind the retina when the subject's eye is in a resting accommodation state due to the addition of a correction power different from the correction power required for optimal correction of the subject's eye. For example, if the measurement proceeds while the subject's eye is in an overcorrected state, there is a possibility that a correct measurement result of the subject's eye cannot be obtained, which is a problem. For example, if glasses or contact lenses are prescribed based on the measurement result of the overcorrected state of the subject's eye, the subject's eye is subjected to more strain than necessary to focus on an object, which may cause eye strain.

[0005] In consideration of the above problems, the present disclosure has as its technical object to provide a subjective optometry device and a subjective optometry program that can correctly obtain measurement results of a subject's eye. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention is characterized by having the following configuration. (1) A subjective eye examination device according to a first aspect of the present disclosure is a subjective eye examination device that is arranged in an optical path of a light projection optical system that projects a visual target light beam toward a test eye, has a correction means that changes the optical characteristics of the visual target light beam, and subjectively measures the optical characteristics of the test eye, and is characterized in that it comprises an anterior eye image acquisition means that acquires an anterior eye image of the test eye during subjective measurement, an overcorrection detection means that detects whether the test eye is in an overcorrected state based on the anterior eye image acquired by the anterior eye image acquisition means, and an operation control means that controls an operation to release the overcorrected state of the test eye based on the detection result detected by the overcorrection detection means. (2) A subjective eye examination program according to a second aspect of the present disclosure is a subjective eye examination program for use in a subjective eye examination device that is arranged in an optical path of a light projection optical system that projects a visual target light beam toward a test eye, has a corrective means for changing the optical characteristics of the visual target light beam, and subjectively measures the optical characteristics of the test eye, and is characterized in that the subjective eye examination device is caused to execute an anterior eye image acquisition step of acquiring an anterior eye image of the test eye during subjective measurement, an overcorrection detection step of detecting whether the test eye is in an overcorrected state based on the anterior eye image acquired in the anterior eye image acquisition step, and an operation control step of controlling an operation to release the overcorrected state of the test eye based on the detection result detected in the overcorrection detection step. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an external view of an optometric apparatus. [Diagram 2] FIG. 13 is a diagram showing a measurement unit for the left eye. [Diagram 3] 1 is a schematic configuration diagram of the inside of an optometry apparatus as viewed from the front. [Figure 4] 2 is a schematic configuration diagram of the inside of the optometry apparatus as viewed from the side. FIG. [Diagram 5]2 is a schematic configuration diagram of the inside of the optometry apparatus as viewed from above. FIG. [Figure 6] FIG. 2 is a diagram showing a control system of the optometric apparatus. [Figure 7] 1 is an example of a reference image. [Figure 8] FIG. 1 is a diagram showing an overcorrected state of a subject's eye. [Figure 9] FIG. 11 is a flow chart of detecting an overcorrection state. [Figure 10] 1 is an example of a reference image. [Figure 11] 13 is an example of an operation screen. [Figure 12] 13 is an example of a graph showing changes in overcorrection information over time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <Summary> An overview of a subjective optometry device according to an embodiment of the present disclosure will be described. The items classified in <> below can be used independently or in conjunction with each other.

[0009] In this embodiment, the overcorrection state of the test eye is a state in which a light beam entering the test eye forms an image behind the retina when the test eye is in a state of accommodation rest, due to the addition of a correction power different from the correction power required for optimal correction of the test eye. In other words, it is a state in which an object is focused behind the retina when the test eye is corrected and observed in a state of accommodation rest. For example, in a myopic eye, a negative power (large negative power) stronger than the negative power required for optimal correction of the test eye is added, and the light beam entering the test eye forms an image behind the retina, which is an overcorrection state. For example, in a hyperopic eye, a positive power (small positive power) weaker than the positive power required for optimal correction of the test eye is added, and the light beam entering the test eye forms an image behind the retina, which is an overcorrection state.

[0010] The subjective optometry device in this embodiment subjectively measures the optical characteristics of the subject's eye. For example, the optical characteristics of the subject's eye may be at least one of the ocular refractive power of the subject's eye (e.g., the spherical power, cylindrical power, and astigmatism axis angle of the subject's eye), contrast sensitivity, and binocular vision function (e.g., the amount of heterophoria, stereoscopic vision function, and the like).

[0011] <Projection optical system> The subjective eye examination device in this embodiment may include a light projection optical system (e.g., a light projection optical system 30). The light projection optical system projects a visual target light beam toward the subject's eye. The light projection optical system may have at least one optical member that guides the visual target light beam toward the subject's eye.

[0012] The light projection optical system may include a target presenting means. The target presenting means presents a target to the eye to be examined. In this case, the light projection optical system projects a target light beam emitted from the target presenting means toward the eye to be examined. For example, a display (for example, the display 31) can be used as the target presenting means. Also, for example, a light source and a DMD (Digital Micromirror Device) can be used as the target presenting means. In general, since a DMD has a high reflectance and is bright, it is possible to maintain the light amount of the target light beam more than when an LCD is used. Also, for example, a visible light source for presenting a target and a target plate can be used as the target presenting means. The target plate is a rotatable disk plate and may have a plurality of targets. On the optical path along which the target light beam is guided to the eye to be examined, the target plate is rotated by a motor or the like, so that the target is switched and positioned.

[0013] In the present embodiment, the subjective optometry device does not necessarily have to include a projection optical system, and may be configured to include a device including a projection optical system separately from the subjective optometry device. In other words, the subjective optometry device may be configured to include at least the correction means described below.

[0014] <Correction means> The subjective eye examination device in this embodiment includes a corrective means (e.g., a control unit 70). For example, the corrective means may include a corrective optical system (e.g., a light projecting optical system 30, a corrective optical system 60) as a part of the configuration of the corrective means. For example, the corrective optical system is disposed in the optical path of the light projecting optical system, and changes the optical characteristics of the visual target light beam. For example, the optical characteristics of the visual target light beam may be at least one of the spherical power, cylindrical power, astigmatism axis angle, etc. of the visual target light beam.

[0015] For example, the correction optical system may be configured to be able to change the optical characteristics of the visual target light beam. For example, the correction optical system may be able to change the optical characteristics of the visual target light beam by controlling an optical element. The optical element may be at least one of a spherical lens, a cylindrical lens, a cross cylinder lens, a rotary prism, a wavefront modulation element, a variable focus lens, and the like. Of course, an optical element different from these optical elements may also be used.

[0016] Also, for example, the correction optical system may correct the spherical power of the subject's eye by optically changing the presentation distance of the optotype relative to the subject's eye. In this case, the optotype presenting means may be moved in the optical axis direction in order to optically change the presentation distance of the optotype. In this case, the optical element (e.g., a spherical lens, etc.) arranged in the optical path may be moved in the optical axis direction in order to optically change the presentation distance of the optotype.

[0017] In addition, the corrective optical system may be configured by combining a configuration for controlling an optical element, a configuration for moving a visual target presenting means in the optical axis direction, and a configuration for moving an optical element arranged in the optical path in the optical axis direction.

[0018] In this embodiment, the correction optical system may be an eye refraction measuring unit (phoropter) that arranges an optical element in front of the eye to be examined. For example, the eye refraction measuring unit may have a variable focus lens and change the refractive power of the variable focus lens. Also, for example, the eye refraction measuring unit may have a lens disk on which a plurality of optical elements are arranged on the same circumference, and a driving means (e.g., a motor) for rotating the lens disk, and the optical elements may be electrically switched by driving the driving means. Of course, the eye refraction measuring unit may have a variable focus lens, a lens disk, and a driving means. When these configurations are provided, the visual target light beam toward the eye to be examined is projected via the eye refraction measuring unit.

[0019] In addition, in this embodiment, the correction optical system may be configured to change the optical characteristics of the visual target light beam by controlling an optical element disposed between a visual target presenting means included in the light projection optical system and an optical member for guiding the visual target light beam emitted from the visual target presenting means to the subject's eye. That is, the correction optical system may be configured as a phantom lens refractometer (phantom correction optical system). In this case, the visual target light beam corrected by the correction optical system is guided to the subject's eye via the optical member.

[0020] The correction optical system may have a pair of correction optical systems for the left eye and the right eye. For example, the correction optical system for the left eye and the correction optical system for the right eye may be composed of the same members, or at least some of the members may be composed of different members. Also, for example, the correction optical system for the left eye and the correction optical system for the right eye may be configured to share at least some of the members constituting each of them.

[0021] <Anterior segment image acquisition means> The subjective eye examination device in this embodiment includes an anterior eye image acquiring means (e.g., a control unit 70). For example, the anterior eye image acquiring means acquires an anterior eye image of the subject's eye. For example, the anterior eye image acquiring means may acquire an anterior eye image during subjective measurement of the subject's eye. The anterior eye image may be at least one of an anterior eye image of the left eye and an anterior eye image of the right eye. The anterior eye image may also be an anterior eye image including the left eye and the right eye.

[0022] The subjective ophthalmology apparatus may include a device for imaging an anterior segment of the subject's eye, separate from the subjective ophthalmology apparatus. In this case, for example, the anterior segment image acquiring means may acquire an anterior segment image by receiving an anterior segment image captured by the device for imaging an anterior segment of the subject's eye. As an example, the device for imaging an anterior segment of the subject's eye may be a wearable device (for example, a glasses-type wearable terminal, a head-mounted display, etc.).

[0023] For example, the subjective ophthalmology examination apparatus may include an anterior eye imaging means (e.g., the observation optical system 50). For example, the anterior eye imaging means captures an anterior eye image during subjective measurement of the subject's eye. In this case, the anterior eye image acquisition means may acquire the anterior eye image captured by the anterior eye imaging means.

[0024] In this embodiment, the anterior eye image acquiring means may acquire an anterior eye image in a state where the subject's eye is not in an overcorrected state as a reference image. For example, the anterior eye image in a state where the subject's eye is not in an overcorrected state may be an anterior eye image in a state where the subject's eye is not corrected (uncorrected state). For example, the anterior eye image in a state where the subject's eye is not in an overcorrected state may be an anterior eye image in a state where the subject's eye is corrected. In this case, the subject's eye may be corrected with a correction power different from that required for optimal correction, and an anterior eye image obtained in a state where a light beam incident on the subject's eye forms an image on the near side of the retina (low correction state) may be used. In this case, the subject's eye may be corrected with a correction power required for optimal correction, and an anterior eye image obtained in a state where a light beam incident on the subject's eye forms an image on the retina may be used. For example, when the subject's eye is in an overcorrected state, the subject's eye may change the thickness of the crystalline lens to focus on the retina, causing pupil constriction. Therefore, as an anterior segment image in which the subject's eye is not in an overcorrected state, an anterior segment image in which the subject's eye is not miotically constricted and the pupil is of a normal size may be acquired.

[0025] Such a reference image may be configured to be acquired prior to subjective measurement of the subject's eye. For example, an anterior segment image serving as a reference image may be received in advance to acquire the reference image. Also, for example, the reference image may be acquired by capturing an image of the anterior segment of the subject's eye at a predetermined timing of an operation performed prior to subjective measurement. As an example, the reference image may be acquired at the timing of starting or ending alignment (positioning) between the subject's eye and the subjective optometry device, or at the timing of starting or ending objective measurement of the subject's eye.

[0026] In addition, such a reference image may be configured to be acquired during subjective measurement of the subject's eye. For example, the reference image may be acquired by capturing an image of the anterior segment of the subject's eye at a predetermined timing during the subjective measurement. As an example, the reference image may be acquired immediately before the optical characteristics of the target light beam are changed based on the correction means.

[0027] In addition, such a reference image may be configured to be acquired after subjective measurement is performed on the subject's eye. For example, the reference image may be acquired by receiving an anterior segment image after the fact. In addition, for example, an appropriate anterior segment image among the anterior segment images acquired during subjective measurement (i.e., a reference image to be described later) may be acquired as the reference image.

[0028] In the present embodiment, the anterior-segment image acquiring means may acquire an anterior-segment image during subjective measurement of the subject's eye as a reference image. For example, the anterior-segment image during subjective measurement of the subject's eye may include an anterior-segment image acquired at least at any timing from the start to the end of the subjective measurement.

[0029] The anterior eye image acquiring means may continuously acquire anterior eye images of the subject's eye at a predetermined timing during the subjective measurement. For example, a reference image of the subject's eye may continuously be acquired at a predetermined timing during the subjective measurement. In this case, the anterior eye image of the subject's eye may be acquired every time a predetermined time elapses during the subjective measurement (i.e., every predetermined time interval). In addition, in this case, the anterior eye image of the subject's eye may be acquired at a specific timing during the subjective measurement. As an example, it may be acquired when the correction power of the subject's eye is changed, etc. More specifically, it may be acquired every time the optical characteristics of the visual target light beam are changed by the correction means.

[0030] <Overcorrection Detection Means> The subjective ophthalmology device in this embodiment includes an overcorrection detection means (e.g., a control unit 70). For example, the overcorrection detection means detects whether or not the subject's eye is in an overcorrected state based on an anterior segment image of the subject's eye. For example, the overcorrection detection means may detect whether or not the subject's eye is in an overcorrected state based on an anterior segment image acquired during subjective measurement of the subject's eye.

[0031] For example, the overcorrection detection means may detect whether the subject's eye is in an overcorrected state by acquiring pupil information of the subject's eye based on an anterior eye image of the subject's eye. For example, the pupil information of the subject's eye may be information that can grasp changes in the pupil. As an example, the pupil information may be at least one of pupil diameter, pupil size, pupil area, etc. As another example, the pupil information may be at least one of the presence or absence of miosis, miosis rate, etc., detected using at least one of pupil diameter, pupil size, pupil area, etc. Of course, as the pupil information, at least one of the presence or absence of mydriasis, mydriasis rate, etc., detected using at least one of pupil diameter, pupil size, pupil area, etc., may be acquired.

[0032] As described above, the overcorrection state of the test eye is a state in which the test eye is in a state where accommodation is paused and the light beam incident on the test eye is imaged behind the retina. However, even if the test eye is in an overcorrection state, the test eye adjusts by changing the thickness of the crystalline lens to image the light beam on the retina. Here, when the test eye adjusts to image the light beam on the retina, a change is observed in the pupil of the test eye. Therefore, by detecting the change in the pupil of the test eye, the overcorrection state of the test eye can be confirmed. For example, the overcorrection detection means may detect the test eye as being in an overcorrection state when the pupil information of the test eye has changed. On the other hand, for example, the overcorrection detection means may detect the test eye as not being in an overcorrection state when the pupil information of the test eye has not changed.

[0033] For example, the overcorrection detection means may detect whether the subject's eye is in an overcorrected state by analyzing the anterior eye image of the subject's eye based on the anterior eye image of the subject's eye. For example, various image processing methods may be applied to the analysis of the anterior eye image. Pupil information may be obtained by detecting at least one change in luminance, saturation, hue, etc.

[0034] For example, the overcorrection detection means may detect whether the subject's eye is in an overcorrected state by comparing a standard image of the subject's eye with a reference image. Also, for example, the overcorrection detection means may detect whether the subject's eye is in an overcorrected state by comparing a current anterior segment image with an anterior segment image captured immediately before, which is an anterior segment image acquired in a subjective measurement of the subject's eye. In this case, for example, the degree of agreement between the two anterior segment images, the change (amount of change) in pupil information in the two anterior segment images, etc. may be compared to detect whether the subject's eye is in an overcorrected state.

[0035] <Operation control means> The subjective optometry device in this embodiment includes an operation control means (e.g., a control unit 70). For example, the operation control means controls an operation for releasing the overcorrected state of the subject's eye based on a detection result of whether the subject's eye is in an overcorrected state. This allows an appropriate response to be taken for the subject's eye, and the subject's eye can be prevented from becoming in an overcorrected state, so that a measurement result of the subject's eye can be correctly obtained.

[0036] For example, the operation control means may control the correcting means to change the correction power for correcting the eye to be examined, as an operation for releasing the overcorrected state of the eye to be examined.

[0037] For example, the operation control means may change the current first correction power for correcting the eye to a second correction power stronger on the positive side than the first correction power. That is, for example, the operation control means may change the first correction power to the second correction power so that the imaging position of the light beam when the first correction power is added to the eye to be examined moves toward the crystalline lens by adding the second correction power (so that the focal length becomes shorter). As an example, in the case of a myopic eye, the first correction power is a predetermined negative power, and the second correction power is a negative power (small negative power) weaker than the predetermined negative power. As an example, in the case of a hyperopic eye, the first correction power is a predetermined positive power, and the second correction power is a positive power (large positive power) stronger than the predetermined positive power.

[0038] For example, the operation control means may change the first correction power to the second correction power according to a change step (stage) of the correction power that can be changed by the correction means. For example, the second correction power may be a correction power that is stronger by one step (one stage) on the positive side than the first correction power. As an example, when the change step of the correction power is 0.25D, the second correction power is a value obtained by adding +0.25D to the first correction power. Of course, the second correction power may be a correction power that is stronger by one step or more on the positive side than the first correction power. The number of steps of the second correction power may be set in advance, or may be arbitrarily selected by the examiner.

[0039] For example, the operation control means may control the correction means to change the correction power for correcting the subject's eye as an operation for releasing the overcorrection state of the subject's eye, thereby adding fogging to the subject's eye. For example, the amount of fogging for the subject's eye may be set in advance, or may be arbitrarily selected by the examiner.

[0040] For example, the operation control means may control the optotype presenting means to optically change the presenting position of the optotype (i.e., the presenting distance of the optotype), thereby changing the correction power for correcting the eye to be examined and adding fogging to the eye to be examined. In this case, the operation control means may move the optotype presenting means in the optical path of the optotype presenting means in the optical axis direction in order to optically change the presenting distance of the optotype. Also, the operation control means may move an optical element (e.g., a spherical lens, etc.) arranged in the optical path of the optotype presenting means in the optical axis direction. Also, an optical member may be inserted or removed in the optical path of the optotype presenting means. Note that at least one of a lens, a prism, a mirror, etc. may be used as the optical member moved or inserted or removed in the optical path of the optotype presenting means. For example, the operation control means may add fogging to the eye to be examined by any of these configurations or a combination thereof.

[0041] For example, the operation control means may output overcorrection information for identifying that the subject's eye is in an overcorrected state as an operation for releasing the overcorrected state of the subject's eye. For example, the overcorrection information may be any information that can identify that the subject's eye is in an overcorrected state. For example, the overcorrection information may directly or indirectly indicate that the subject's eye is in an overcorrected state.

[0042] For example, the operation control means may output the detection result detected by the overcorrection detection means as overcorrection information. In this case, the detection result (overcorrection information) may directly output pupil information of the subject's eye (for example, at least one of pupil diameter, pupil size, pupil area, presence or absence of miosis, miosis rate, etc.).

[0043] For example, the operation control means may output, as the overcorrection information, notification information based on the detection result detected by the overcorrection detection means. For example, the notification information may be information for informing the examiner that the subject's eye is in an overcorrected state, or that the subject's eye is suspected to be in an overcorrected state, etc. In other words, the notification information may be information for supporting the examiner in determining whether or not the subject's eye is in an overcorrected state. As an example, the notification information may be information indicating at least one of the presence or absence of overcorrection of the subject's eye, the appropriateness or non-adequateness of the correction state of the subject's eye, etc.

[0044] For example, the operation control means may output, as the overcorrection information, guidance information based on the detection result detected by the overcorrection detection means. For example, the guidance information may be information for guiding the examiner. In other words, the guidance information may be information for supporting the progress of the subjective examination by the examiner. As an example, the guidance information may be at least one of information indicating the examiner's next operation, information indicating instructions to the subject, and the like.

[0045] For example, the operation control means may control the display means and cause the display means to display the overcorrection information. Also, for example, the operation control means may control the sound generation means (for example, a speaker) and cause the sound generation means to generate the overcorrection information as sound. Also, for example, the operation control means may control the notification means (for example, a lamp) and cause the notification means to light up or blink to display the overcorrection information. Also, for example, the operation control means may control the printing means and cause the printing means to print the overcorrection information. Also, for example, the operation control means may control the external storage means (for example, a memory or a server) and transmit the overcorrection information to the external storage means. Of course, for example, the operation control means may execute a combination of these controls, or may execute a control different from these controls.

[0046] For example, when the operation control means controls the display means, a message may be displayed on the display means as the overcorrection information, or a change over time in the overcorrection information described later may be displayed as a graph. For example, the overcorrection information may be displayed by highlighting the screen on the display means. As an example, the overcorrection information may be displayed by at least one of reversing or changing the color of the screen, blinking the screen, changing the display size, and the like. For example, the overcorrection information may be displayed by displaying a sign (for example, at least one of a window, a mark, an icon, a letter, a number, a symbol, and the like) on the display means. Of course, the overcorrection information may be displayed by further highlighting such a sign, for example.

[0047] For example, the operation control means may execute at least one of the following controls: changing the correction power for correcting the eye to be examined, applying mist to the eye to be examined, outputting overcorrection information, etc. Also, for example, the operation control means may execute a combination of these controls. This allows appropriate measures to be taken to remove the overcorrection state of the eye to be examined, so that the measurement results of the eye to be examined can be obtained correctly.

[0048] In this embodiment, the operation control means may output a graph showing the change in overcorrection information over time based on the anterior segment images continuously acquired at a predetermined timing during the subjective measurement of the subject's eye. In other words, a graph showing the change in overcorrection information over time including the predetermined timing of the subjective test may be output. The predetermined timing of the subjective test may be a timing at a predetermined time interval, or may be a timing each time the optical characteristics of the visual target light beam are changed by the correcting means. This makes it easy to confirm at what timing during the subjective measurement the subject's eye becomes overcorrected.

[0049] For example, the operation control means may output an alert to notify the examiner that the examinee's eye is in an overcorrected state (suspected of being in an overcorrected state) together with a graph showing the change over time in the overcorrection information. For example, the alert may be anything that can call the examiner's attention. As an example, the alert may be at least one of a message superimposed on the graph, highlighting the graph (at least one of inverting or changing the color, blinking, etc.), etc.

[0050] The present disclosure is not limited to the device described in the present embodiment. For example, the terminal control software (program) performing the functions of the above embodiment can be supplied to a device or a system via a network or various storage media, and a control device (e.g., a CPU) of the device or the system can read and execute the program.

[0051] Such terminal control software may include a self-eye examination program that automatically proceeds with the eye examination based on an answer entered by the subject after visually recognizing the test optotype. In this case, the self-eye examination program may execute an anterior eye image acquisition step of acquiring an anterior eye image of the subject's eye during subjective measurement, an overcorrection detection step of detecting whether the subject's eye is in an overcorrected state based on the anterior eye image acquired in the anterior eye image acquisition step, and an operation control step of controlling an operation to release the overcorrected state of the subject's eye based on the detection result detected in the overcorrection detection step.

[0052] <Example> An example of a subjective optometry apparatus (hereinafter, optometry apparatus) according to this embodiment will be described.

[0053] FIG. 1 is an external view of an optometry apparatus 100. For example, the optometry apparatus 100 includes a housing 2, a presentation window 3, a forehead rest 4, a chin rest 5, a controller 6, an imaging unit 90, and the like. The housing 2 includes a measurement unit 7, a deflection mirror 81, a reflection mirror 84, a concave mirror 85, and the like inside. The presentation window 3 is used to present a visual target to the eye E to be examined. The forehead rest 4 and the chin rest 5 are used to keep the distance between the eye E to be examined and the optometry apparatus 1 constant. The controller 6 includes a monitor 6a, a switch unit 6b, and the like. The monitor 6a displays various information (e.g., measurement results of the eye to be examined, etc.). The monitor 6a may be a touch panel that also functions as the switch unit 6b. The switch unit 6b is used to perform various settings (e.g., input of a start signal, etc.). A signal corresponding to an operation instruction from the controller 6 is output to the control unit 70 by wired communication or wireless communication.

[0054] The imaging unit 90 is used to capture an image of the face of the subject and adjust the position of the subject's eye in the Y direction. The imaging unit 90 includes an imaging optical system (not shown). For example, the imaging optical system may be composed of an imaging element and a lens.

[0055] <Measurement section> The measurement unit 7 includes a left eye measurement unit 7L and a right eye measurement unit 7R. The left eye measurement unit 7L and the right eye measurement unit 7R are configured from the same material. Of course, the left eye measurement unit 7L and the right eye measurement unit 7R may be configured from at least a part of different materials. The measurement unit 7 has a pair of left and right subjective measurement units and a pair of left and right objective measurement units (details will be described later). The target light beam and the measurement light beam from the measurement unit 7 are guided to the subject's eye E through the presentation window 3.

[0056] 2 is a diagram showing the left eye measurement unit 7L. The right eye measurement unit 7R has the same configuration as the left eye measurement unit 7L, so it is omitted. For example, the left eye measurement unit 7L includes an objective measurement optical system 10, a subjective measurement optical system 25, a first target projection optical system 45, a second target projection optical system 46, an observation optical system 50, etc.

[0057] <Objective measurement optical system> The objective measuring optical system 10 is used as a part of an objective measuring unit that objectively measures the optical characteristics of the subject's eye E. In this embodiment, the ocular refractive power of the subject's eye E is measured as the optical characteristic of the subject's eye E. For example, the objective measuring optical system 10 is composed of a projection optical system 10a and a light receiving optical system 10b.

[0058] The projection optical system 10a projects a spot-shaped measurement target onto the fundus of the subject's eye E through the center of the pupil of the subject's eye E. For example, the projection optical system 10a includes a light source 11, a relay lens 12, a hole mirror 13, a prism 15, an objective lens 93, a dichroic mirror 35, a dichroic mirror 29, and the like. The light source 11 emits a measurement light beam. The light source 11 is conjugate with the fundus of the subject's eye E. The hole of the hole mirror 13 is conjugate with the pupil of the subject's eye E. The prism 15 is a light beam deflecting member. The prism 15 is disposed at a position away from the position conjugate with the pupil of the subject's eye E, and decenters the measurement light beam passing through the prism 15 with respect to the optical axis L1. The prism 15 is driven to rotate around the optical axis L1 by a drive unit (motor) 23. The dichroic mirror 35 makes the optical path of the objective measurement optical system 10 and the optical path of the subjective measurement optical system 25 a common optical path. In other words, the optical axis L1 of the objective measurement optical system 10 and the optical axis L2 of the subjective measurement optical system 25 are coaxial. The dichroic mirror 29 is an optical path branching member. The dichroic mirror 29 reflects the measurement light beam from the projection optical system 10a and the target light beam from the projection optical system 30 (described later) and guides them to the subject's eye E.

[0059] The light receiving optical system 10b extracts the fundus reflected light beam reflected by the fundus of the subject's eye E in a ring shape through the pupil periphery of the subject's eye E. For example, the light receiving optical system 10b includes a dichroic mirror 29, a dichroic mirror 35, an objective lens 93, a prism 15, a hole mirror 13, a relay lens 16, a mirror 17, a light receiving aperture 18, a collimator lens 19, a ring lens 20, an image sensor 22, and the like. The ring lens 20 is composed of a lens portion formed in a ring shape and a light shielding portion in which a light shielding coating is applied to an area other than the lens portion. The ring lens 20 is in a positional relationship optically conjugate with the pupil of the subject's eye E. The light receiving aperture 18 and the image sensor 22 are in a conjugate relationship with the fundus of the subject's eye E. The output from the image sensor 22 is input to the control unit 70.

[0060] In this embodiment, the prism 15 is disposed on a common optical axis of the projection optical system 10a and the light receiving optical system 10b. For example, the measurement light beam from the projection optical system 10a passes through the prism 15 and enters the subject's eye E, and the fundus reflected light beam reflected by the fundus of the subject's eye E passes through the same prism 15. Therefore, in the subsequent optical systems, the projection light beam and the fundus reflected light beam (received light beam) are scanned inversely as if there was no decentering of the projection light beam and the fundus reflected light beam (received light beam) on the pupil.

[0061] <Subjective Measuring Optical System> The subjective measurement optical system 25 is used as a part of a subjective measurement unit that subjectively measures the optical characteristics of the subject's eye E. In this embodiment, the ocular refractive power of the subject's eye E is measured as the optical characteristics of the subject's eye E. For example, the subjective measurement optical system 25 is composed of a light projection optical system 30 and a correction optical system 60.

[0062] <Projection optical system> The light projection optical system 30 projects a visual target light flux toward the subject's eye E. For example, the light projection optical system 30 includes a display 31, a light projection lens 33, a light projection lens 34, a reflecting mirror 36, an objective lens 92, a dichroic mirror 35, a dichroic mirror 29, etc. A visual target (a fixation target, a test visual target, etc.) is displayed on the display 31.

[0063] <Correction optical system> The correction optical system 60 is disposed in the optical path of the projection optical system 30. The correction optical system 60 changes the optical characteristics of the visual target light beam emitted from the display 31. For example, the correction optical system 60 includes an astigmatism correction optical system 63, a driving mechanism 39, and the like. The astigmatism correction optical system 63 is used to correct the cylindrical power and astigmatism axis angle of the subject's eye E. The astigmatism correction optical system 63 is disposed between the projection lens 33 and the projection lens 34. The astigmatism correction optical system 63 is composed of two positive cylindrical lenses 61a and 61b having the same focal length. The cylindrical lenses 61a and 61b are independently rotated around the optical axis L2 by the driving of the rotation mechanisms 62a and 62b.

[0064] In this embodiment, the cylindrical lens 61a and the cylindrical lens 61b are used as the astigmatism correcting optical system 63, but the present invention is not limited to this. The astigmatism correcting optical system 63 may be configured to correct the cylindrical power, the astigmatism axis angle, etc. As an example, a corrective lens may be inserted into or removed from the optical path of the projection optical system 30.

[0065] The light source 11 and relay lens 12 included in the projection optical system 10a, the light receiving diaphragm 18, collimator lens 19, ring lens 20, and image sensor 22 included in the light receiving optical system 10b, and the display 31 included in the light projection optical system 30 can be moved integrally in the optical axis direction by a drive mechanism 39. In other words, the display 31, light source 11, relay lens 12, light receiving diaphragm 18, collimator lens 19, ring lens 20, and image sensor 22 are synchronized as a drive unit 95, and are moved integrally by the drive mechanism 39. The drive mechanism 39 is composed of a motor and a slide mechanism.

[0066] The driving mechanism 39 moves the display 31 in the direction of the optical axis L2 by moving the driving unit 95 in the direction of the optical axis. This allows the subject's eye E to be clouded in the objective measurement. In the subjective measurement, the presentation distance of the optotype to the subject's eye E can be optically changed to correct the spherical power of the subject's eye E. That is, the configuration for moving the display 31 in the direction of the optical axis L2 is used as a spherical correction optical system for correcting the spherical power of the subject's eye E, and the spherical power of the subject's eye E is corrected by changing the position of the display 31. The configuration of the spherical correction optical system may be different from that of this embodiment. For example, the spherical power may be corrected by arranging a number of optical elements in the optical path. Also, for example, the spherical power may be corrected by arranging a lens in the optical path and moving the lens in the direction of the optical axis.

[0067] Further, the driving mechanism 39 moves the driving unit 95 in the optical axis direction, thereby moving the light source 11, the relay lens 12, and the image sensor 22 from the light receiving aperture 18 in the optical axis L1 direction. As a result, the light source 11, the light receiving aperture 18, and the image sensor 22 are arranged so as to be optically conjugate with the fundus of the subject's eye E. Regardless of the movement of the driving unit 95, the hole mirror 13 and the ring lens 20 are arranged so as to be conjugate with the pupil of the subject's eye E at a constant magnification. Therefore, the fundus reflected light beam, which is the measurement light beam of the projection optical system 10a, is always incident on the ring lens 20 of the light receiving optical system 10b as a parallel light beam, and a ring-shaped light beam of the same size as the ring lens 20 is imaged by the image sensor 22 in a focused state, regardless of the ocular refractive power of the subject's eye E.

[0068] <First target projection optical system and second target projection optical system> The first target projection optical system 45 and the second target projection optical system 46 are disposed between the dichroic mirror 29 and a deflection mirror 81 (described later). The first target projection optical system 45 emits near-infrared light for projecting an alignment target at infinity onto the cornea of ​​the subject's eye E. The second target projection optical system 46 is disposed at a position different from the first target projection optical system 45, and emits near-infrared light for projecting an alignment target at finite distance onto the cornea of ​​the subject's eye. The near-infrared light (alignment light) emitted from the second target projection optical system 46 is also used as anterior eye imaging light for imaging the anterior eye of the subject's eye by the observation optical system 50.

[0069] <Observation optical system> The observation optical system (imaging optical system) 50 includes a dichroic mirror 29, an objective lens 103, an imaging lens 51, an imaging element 52, etc. The dichroic mirror 29 transmits the anterior eye observation light and the alignment light. The imaging element 52 has an imaging surface arranged at a position conjugate with the anterior eye of the subject's eye E. The output from the imaging element 52 is input to the control unit 70. As a result, an anterior eye image of the subject's eye E is captured by the imaging element 52 and displayed on the monitor 6a. The observation optical system 50 also serves as an optical system for detecting an alignment index image formed on the cornea of ​​the subject's eye E by the first index projecting optical system 45 and the second index projecting optical system 46, and the position of the alignment index image is detected by the control unit 70.

[0070] <Internal structure of the optometry device> The internal configuration of the optometry apparatus 100 will be described. Fig. 3 is a schematic diagram of the inside of the optometry apparatus 100 as viewed from the front. Fig. 4 is a schematic diagram of the inside of the optometry apparatus 100 as viewed from the side. Fig. 5 is a schematic diagram of the inside of the optometry apparatus 100 as viewed from above. For ease of explanation, Figs. 4 and 5 only show the optical axis of the left eye measurement unit 7L.

[0071] The optometry apparatus 100 includes an objective measurement unit. For example, the objective measurement unit includes a measurement unit 7, a deflection mirror 81, a reflection mirror 84, a concave mirror 85, and the like. The optometry apparatus 100 also includes a subjective measurement unit. For example, the subjective measurement unit includes a measurement unit 7, a deflection mirror 81, a reflection mirror 84, a concave mirror 85, and the like. The objective measurement unit and the subjective measurement unit are not limited to this configuration. For example, the configuration may not include the reflection mirror 84. In this case, the light beam from the measurement unit 7 may be irradiated from an oblique direction with respect to the optical axis L of the concave mirror 85 after passing through the deflection mirror 81. In addition, for example, the configuration may include a half mirror. In this case, the light beam from the measurement unit 7 may be irradiated from an oblique direction with respect to the optical axis L of the concave mirror 85 through the half mirror.

[0072] For example, the deflection mirror 81 has a left-eye deflection mirror 81L and a right-eye deflection mirror 81R that are provided in a pair on the left and right sides. For example, the deflection mirror 81 is disposed between the correction optical system 60 and the subject's eye E. That is, the correction optical system 60 in this embodiment has a left-eye corrective optical system and a right-eye corrective optical system that are provided in a pair on the left and right sides, and the left-eye deflection mirror 81L is disposed between the left-eye corrective optical system and the left eye EL, and the right-eye deflection mirror 81R is disposed between the right-eye corrective optical system and the right eye ER. For example, the deflection mirror 81 is preferably disposed at a pupil conjugate position.

[0073] For example, the left-eye deflection mirror 81L reflects the light beam projected from the left-eye measurement unit 7L and guides it to the left eye EL. Also, for example, the left-eye deflection mirror 81L reflects the fundus reflection light beam from the left eye EL and guides it to the left-eye measurement unit 7L. For example, the right-eye deflection mirror 81R reflects the light beam projected from the right-eye measurement unit 7R and guides it to the right eye ER. Also, for example, the right-eye deflection mirror 81R reflects the fundus reflection light beam from the right eye ER and guides it to the right-eye measurement unit 7R.

[0074] For example, the deflection mirror 81 is rotationally moved by the drive unit 82. For example, the rotational movement of the deflection mirror 81 can deflect an apparent light beam for forming an image of the visual target light beam in front of the subject's eye, and optically correct the formation position of the image of the visual target light beam. For example, the drive unit 82 is composed of a motor or the like. For example, the drive unit 82 rotates the deflection mirror 81 about a rotation axis in the horizontal direction (X direction) and a rotation axis in the vertical direction (Y direction). That is, the drive unit 82 rotates the deflection mirror 81 in the XY direction. Note that the rotation of the deflection mirror 81 may be either the horizontal direction or the vertical direction. For example, the drive unit 82 has a drive unit 82L for driving the left-eye deflection mirror 81L and a drive unit 82R for driving the right-eye deflection mirror 81R.

[0075] In this embodiment, the configuration using the deflection mirror 81 as the deflection member that reflects and guides the light beam projected from the measurement unit 7 to the subject's eye E has been described as an example, but the present invention is not limited to this. The deflection member may be a prism, a lens, or the like as long as it can reflect and guide the light beam projected from the measurement unit 7 to the subject's eye E.

[0076] Also, for example, a plurality of deflection mirrors 81 may be provided in each of the optical path for the left eye and the optical path for the right eye. For example, a configuration in which two deflection mirrors are provided in each of the optical path for the left eye and the optical path for the right eye (for example, a configuration in which two deflection mirrors are provided in the optical path for the left eye, etc.) can be mentioned. In this case, one deflection mirror may be rotated in the X direction, and the other deflection mirror may be rotated in the Y direction. For example, by rotating and moving the deflection mirror 81, it is possible to deflect the apparent light beam for forming an image of the visual target light beam in front of the subject's eye, and optically correct the formation position of the image of the visual target light beam.

[0077] For example, the concave mirror 85 guides the visual target light beam that has passed through the correction optical system 60 to the subject's eye E, and forms an image of the visual target light beam that has passed through the correction optical system 60 in front of the subject's eye E. For example, the concave mirror 85 is shared by the left eye measurement unit 7L and the right eye measurement unit 7R. For example, the concave mirror 85 is shared by the left eye optical path including the left eye correction optical system and the right eye optical path including the right eye correction optical system. That is, the concave mirror 85 is disposed at a position where both the left eye optical path including the left eye correction optical system and the right eye optical path including the right eye correction optical system pass through. Of course, the concave mirror 85 does not have to be configured to be shared by the left eye optical path and the right eye optical path. That is, a concave mirror may be provided in each of the left eye optical path including the left eye correction optical system and the right eye optical path including the right eye correction optical system. For example, the concave mirror 85 guides the visual target light flux that has passed through the correction optical system 60 to the subject's eye E, and forms an image of the visual target light flux that has passed through the correction optical system 60 in front of the subject's eye E.

[0078] The deflection mirror 81 is driven by a drive unit 83 (e.g., a motor or the like). For example, the drive unit 83 has a left drive unit 83L for driving the left-eye deflection mirror 81L and a right drive unit 83R for driving the right-eye deflection mirror 81R. Each deflection mirror is moved in the X direction by the drive unit 83. For example, by moving the left-eye deflection mirror 81L and the right-eye deflection mirror 81R, the distance between the left-eye deflection mirror 81L and the right-eye deflection mirror 81R is changed, and the distance in the X direction between the left-eye optical path and the right-eye optical path can be changed according to the interpupillary distance of the test eye E.

[0079] Further, the measurement unit 7 is driven by a drive unit 9 (e.g., a motor, etc.). For example, the drive unit 9 has a left drive unit 9L for driving the left eye measurement unit 7L and a right drive unit 9R for driving the right eye measurement unit 7R. Each measurement unit is moved in the X direction by the drive unit 9. For example, the left eye measurement unit 7L and the right eye measurement unit 7R are moved, so that the distance between each measurement unit and the deflection mirror 81 changes, and the presentation position in the Z direction of the visual target light beam from each measurement unit is changed. This allows the measurement unit 7 to be adjusted in the Z direction so that the visual target light beam corrected by the correction optical system 60 is guided to the subject's eye E and an image of the visual target light beam corrected by the correction optical system 60 is formed on the fundus of the subject's eye E.

[0080] <Optical path of subjective measurement unit> The optical path of the subjective measurement section will be described by taking the optical path for the left eye as an example. The optical path for the right eye has the same configuration as the optical path for the left eye. The visual target light beam emitted from the display 31 of the subjective measurement optical system 25 reaches the left eye EL via each optical member. For example, the visual target light beam is guided from the left eye measurement section 7L to the left eye deflection mirror 81L by passing through the optical members from the light projecting lens 33 to the dichroic mirror 29 in order. Furthermore, the visual target light beam is reflected by the left eye deflection mirror 81L and guided to the left eye EL via the reflection mirror 84 and the concave mirror 85.

[0081] As a result, an image of the visual target light beam corrected by the correction optical system 60 is formed on the fundus of the left eye EL based on the eyeglass wearing position of the left eye EL (for example, about 12 mm from the corneal apex position). Therefore, adjustment of the spherical power by the correction optical system (in this embodiment, driving of the drive mechanism 39) is performed in front of the eye, which is equivalent to placing the astigmatism correcting optical system 63 in front of the eye. The subject can collimate the image of the visual target light beam optically formed in front of the eye at a predetermined test distance via the concave mirror 85 in a natural state.

[0082] <Control Unit> 6 is a diagram showing a control system of the optometry apparatus 100. The control unit 70 includes a CPU (processor), a RAM, a ROM, and the like. For example, the CPU controls each component in the optometry apparatus 100. For example, the RAM temporarily stores various types of information. For example, the ROM stores various programs, optotypes, initial values, and the like for controlling the operation of the optometry apparatus 100. The control unit 70 may be composed of multiple control units (i.e., multiple processors).

[0083] For example, the control unit 70 is electrically connected to various components such as the monitor 6a, the light source 11, the image sensor 22, the display 31, the image sensor 52, and a non-volatile memory 75 (hereinafter, memory 75). In addition, for example, the control unit 70 is electrically connected to the drive unit 9, the drive unit 82, the drive unit 83, the drive mechanism 39, and the like. For example, the memory 75 is a non-transient storage medium that can retain the stored contents even if the power supply is cut off. For example, the memory 75 can be a hard disk drive, a flash ROM, a USB memory, or the like.

[0084] <Control action> The control operation of the optometric apparatus 100 having the above-mentioned configuration will be described.

[0085] <Alignment> First, the eye E is aligned with the measurement unit 7. For example, the examiner instructs the subject to place his / her face against the forehead rest 4 and the chin rest 5 and observe the presentation window 3. The examiner also operates the switch unit 6b to select a switch for starting alignment (positioning) between the eye E and the measurement unit 7. The control unit 70 projects an alignment index image by the first index projecting optical system 45 and the second index projecting optical system 46 onto the cornea of ​​the eye E in response to an input signal from the switch unit 6b. The control unit 70 also detects the anterior segment of the eye E with the observation optical system 50 and captures an anterior segment image including the alignment index image. Furthermore, the control unit 70 detects the deviations of the measurement unit 7 in the X direction, Y direction, and Z direction with respect to the eye E based on the alignment index image, and moves the measurement unit 7 based on this deviation. This completes the alignment.

[0086] <Acquisition of a reference image> Next, a reference image used to detect an overcorrected state of the subject's eye (described in detail later) is obtained. For example, the control unit 70 captures an anterior eye image of the subject's eye E based on an alignment completion signal of the subject's eye E, and stores the image in the memory 75. In this embodiment, such an anterior eye image captured after the alignment of the subject's eye E is completed and before the subjective measurement of the subject's eye E is started is used as the reference image.

[0087] 7 is an example of a reference image 110 of the subject's eye E. For example, the control unit 70 acquires pupil information related to the pupil of the subject's eye E by previously analyzing the reference image 110 of the subject's eye E. For example, the pupil information may be any information that can determine a change in the pupil. As an example, the pupil information may be at least any one of information such as pupil diameter, pupil size, and pupil area.

[0088] In this embodiment, a case where the pupil diameter is acquired as pupil information of the subject's eye E is taken as an example. For example, various image processing methods can be used to calculate the pupil diameter. As an example, the control unit 70 may detect the luminance value of each pixel in the reference image 110 and detect the pupil P from the rise of the luminance value or the like. The control unit 70 may also calculate the pupil diameter P1 by obtaining the pupil center position Pc by circular approximation of the pupil P and obtaining the distance connecting the outer edge of the pupil P and the pupil center position Pc. The control unit 70 stores the pupil diameter P1 of the reference image 110 in the memory 75.

[0089] <Subjective measurement> When the alignment of the test eye E is completed and a reference image of the test eye E is acquired, a subjective measurement of the test eye E is started. For example, in the subjective measurement of the test eye E, a red-green test, a cross cylinder test, a visual acuity test, and the like are performed in this order. For example, the red-green test is a test for adjusting the spherical power set as the initial value of the test eye E to an appropriate spherical power. For example, the cross cylinder test is a test for adjusting the cylindrical power and the cylindrical axis angle set as the initial value of the test eye E to an appropriate cylindrical power and cylindrical axis angle. For example, the visual acuity test is a test for measuring the highest visual acuity value in a state where the test eye E is corrected with an appropriate spherical power, an appropriate cylindrical power, and an appropriate cylindrical axis angle.

[0090] In this embodiment, a red-green test of the subject's eye E will be described as an example. For example, in the red-green test, it is possible to determine whether the state of the subject's eye E corrected with a desired spherical power corresponds to myopia, emmetropia, or hyperopia. For example, if the test target that the subject can clearly see is red, it is determined to be myopic, if it is green, it is determined to be hyperopic, and if it is about the same, it is determined to be emmetropia.

[0091] The examiner operates the switch unit 6b and selects a switch for starting a red-green test of the subject's eye E. In response to an input signal from the switch unit 6b, the control unit 70 causes a predetermined test optotype to be displayed on the display 31 (step S1 in FIG. 9). For example, a red-green optotype is displayed on the display 31 here.

[0092] Furthermore, the examiner operates the switch unit 6b to set an initial value of the correction power for correcting the subject's eye E (step S2 in FIG. 9). For example, the examiner sets initial values ​​of the spherical power, the cylindrical power, and the astigmatism axis angle based on the objective refractive power of the subject's eye E. For example, the correction power set as the initial value of the subject's eye E may be a power obtained by adding +0.50D to the objective refractive power.

[0093] The control unit 70 controls at least one of the light projection optical system 30 and the correction optical system 60 in response to an input signal from the switch unit 6b. For example, the control unit 70 generates spherical power by moving the display 31 in the optical axis direction. Also, for example, the control unit 70 generates at least one of cylindrical power and astigmatism axis angle by rotating the cylindrical lens 61a and the cylindrical lens 61b around the optical axis. As a result, the subject's eye E is corrected with a predetermined correction power.

[0094] In this embodiment, it is assumed that the subject's eye E is myopic, and the spherical power of the objective refractive power of the subject's eye E is -3.00D, the cylindrical power is 0.00D, and the cylindrical axis angle is 0 degrees. In this case, the control unit 70 positions the display 31 at a position equivalent to -2.50D, and adjusts the rotation angles of the cylindrical lenses 61a and 61b so that the cylindrical lenses 61a and 61b are not combined. As a result, the subject's eye E is corrected with a spherical power of -0.50D and a cylindrical power of 0.00D, and the cylindrical axis angle of the subject's eye E is adjusted to 0 degrees.

[0095] The examiner changes the spherical power for correcting the subject's eye E based on the subject's answer to the test optotype. For example, the change step (stage) of the spherical power for correcting the subject's eye E can be changed in increments of 0.25D. For example, if the subject answers that he / she can clearly see the red optotype, the examiner judges the subject's eye E to be in a myopic state, and changes the spherical power of the subject's eye E by one step to the negative side (here, -0.25D is added to the current -2.50D to change it to -2.75D). Furthermore, the examiner repeats the change of the spherical power for correcting the subject's eye E by one step based on the subject's answer to the test optotype. Here, if the subject answers that he / she can see the red optotype and the green optotype to the same extent, the examiner judges the subject's eye E to be in a normal state, and ends the test. For example, if the subject answers that he or she can clearly see the green target, the subject's eye E is determined to be hyperopic, and the spherical power of the subject's eye E is changed by one step to the positive side (for example, adding +0.25D to -3.50D to make it -3.25D).

[0096] Since the subject's eye E in this embodiment is a myopic eye, the state of the subject's eye E being hyperopic is, in other words, an overcorrected state of the subject's eye E. For example, the overcorrected state of the subject's eye E is a state in which a light beam incident on the subject's eye is imaged behind the retina by adding a correction power different from the correction power required for optimal correction of the subject's eye E.

[0097] However, for example, in the above-mentioned red-green test, even if the examinee answers that the visibility of the test target is the same, the examinee's eye E may actually be in an overcorrected state. More specifically, even if the examinee's eye E is in an overcorrected state in which a stronger negative power than that required for optimal correction is added, the examinee's eye E may be able to see the test target by changing the thickness of the crystalline lens to focus on the retina, and may be judged to be in a state of emmetropia.

[0098] FIG. 8 is a diagram for explaining the overcorrection state of the subject's eye E. FIG. 8(a) shows the imaging position of the visual target light beam L4 when the subject's eye E is corrected with the optimal negative power. FIG. 8(b) and FIG. 8(c) show the imaging position of the visual target light beam L4 when the subject's eye is corrected with a negative power stronger than the optimal negative power. Normally, when the subject answers that the appearance of the test visual target is the same, as shown in FIG. 8(a), the subject's eye E is in a state of accommodation rest, and the visual target light beam from the display 31 is imaged at the fundus position t1 (that is, in a state of emmetropia). For example, the control unit 70 acquires the negative power when the subject's eye E is corrected as the optimal spherical power (here, -3.00D) and stores it in the memory 75. Also, when the subject answers that the target is green, the subject's eye E is in a state of accommodation rest, and the target light beam from the display 31 is focused at a position t2 behind the fundus, as shown in Fig. 8(b) (i.e., a state of hyperopia and overcorrection). For example, the negative power when correcting the subject's eye E is stronger than the optimal spherical power.

[0099] On the other hand, when the subject's eye E adjusts in FIG. 8(b), the imaging position of the target light beam from the display 31 changes as shown in FIG. 8(c). For example, the subject's eye E may adjust when the test target is difficult to see. More specifically, the subject's eye E can adjust the thickness of the crystalline lens S to adjust the spherical refractive power of the subject's eye E, thereby imaging the target light beam from the display 31 at the fundus position t1. In this case, the subject's eye E can easily focus on both the red target and the green target, even though the subject's eye E is in an overcorrected state. Therefore, the subject may answer that the test target is visible to the same extent, and the correct test result may not be obtained.

[0100] Therefore, in this embodiment, it is detected whether or not the subject's eye E is in an overcorrected state in a red-green test of the subject's eye E. For example, since it is known that the subject's eye E undergoes miosis when it is in an overcorrected state, whether or not the subject's eye E is in an overcorrected state is detected by capturing a change in the pupil each time the spherical power for correcting the subject's eye E is changed.

[0101] Hereinafter, detection of an overcorrected state of the subject's eye E will be described in detail with reference to the flowchart of Fig. 9. After the subject's eye E is corrected to an initial value, a reference image used to detect an overcorrected state of the subject's eye E is acquired (step S3). For example, the control unit 70 captures an image of the anterior segment of the subject's eye E based on an adjustment completion signal of the display 31 (and the cylindrical lens 61a and the cylindrical lens 61) and stores it in the memory 75.

[0102] 10 is an example of a reference image 120 of the subject's eye E. For example, the control unit 70 analyzes the reference image 120 of the subject's eye E and calculates the pupil diameter of the subject's eye E. Note that the calculation of the pupil diameter in the standard image 110 of the subject's eye E and the calculation of the pupil diameter in the reference image 120 of the subject's eye E can be considered to be the same, so they will not be described here. The control unit 70 stores the pupil diameter P2 in the reference image 120 in the memory 75.

[0103] Next, based on the standard image 110 and the reference image 120 of the subject's eye E, it is detected whether the subject's eye is overcorrected (step S4). For example, the control unit 70 detects whether the subject's eye E is overcorrected by comparing the pupil diameter P1 of the standard image 110 with the pupil diameter P2 of the reference image 120 of the subject's eye E. As an example, the control unit 70 may detect that the subject's eye E is not overcorrected when the pupil diameter P1 and the pupil diameter P2 match (i.e., when the amount of change in the pupil diameter P2 relative to the pupil diameter P1 is zero). As another example, the control unit 70 may detect that the subject's eye E is overcorrected when the pupil diameter P1 and the pupil diameter P2 do not match (i.e., when the amount of change in the pupil diameter P2 relative to the pupil diameter P1 is not zero).

[0104] In addition, a tolerance range for the amount of change between the pupil diameter P1 of the standard image 110 and the pupil diameter P2 of the reference image 120 (for example, a 10% change) may be set. In this case, the control unit 70 may detect whether the subject's eye E is in an overcorrected state based on whether the amount of change in the pupil diameter P2 relative to the pupil diameter P1 exceeds the tolerance range. As an example, the control unit 70 may detect that the subject's eye E is not in an overcorrected state if the amount of change in the pupil diameter P2 relative to the pupil diameter P1 falls within the tolerance range. Also, as an example, the control unit 70 may detect that the subject's eye E is in an overcorrected state when the amount of change in the pupil diameter P2 relative to the pupil diameter P1 exceeds the tolerance range.

[0105] When it is detected that the subject's eye E is in an overcorrected state (step S4: YES), as an operation for releasing the overcorrected state of the subject's eye, overcorrection information for identifying that the subject's eye E is in an overcorrected state is output (step S5). For example, the control unit 70 causes at least the overcorrection information to be displayed on the monitor 6a based on a detection completion signal of the overcorrected state of the subject's eye E.

[0106] 11 is an example of an operation screen 200 on the monitor 6a. For example, the operation screen 200 can display a current correction power 210 for correcting the subject's eye E, a reference image 110, a calculation result 221 of a pupil diameter P1, a reference image 120, a calculation result 222 of a pupil diameter P2, overcorrection information 223, and the like. For example, a line that approximates a pupil to a circle may be superimposed on the reference image 110 and the reference image 120 of the subject's eye E. Also, for example, in addition to the calculation result 221 of the pupil diameter P1 and the calculation result 222 of the pupil diameter P2, the amount of change in the pupil diameter P2 relative to the pupil diameter P1 may be displayed.

[0107] For example, the overcorrection information 223 may be a message notifying the suspicion of overcorrection. Of course, for example, the overcorrection information 223 may highlight (for example, bold, underline, change the text color, etc.) at least one of the current correction power 210, the calculation result 221 of the pupil diameter P1, the calculation result 222 of the pupil diameter P2, etc., instead of or together with the message notifying the suspicion of overcorrection. Furthermore, for example, the overcorrection information 223 is not limited to being displayed on the monitor 6a, and may be output by at least one of lighting or blinking of a lamp, generation of a voice announcement, etc.

[0108] If it is detected that the subject's eye E is not in an overcorrected state (step S4: NO), the overcorrection information 223 is not output to the operation screen 200. At this time, the display field for the overcorrection information 223 on the operation screen 200 may be left blank, or a message may be displayed indicating that the pupil diameter of the subject's eye E is normal, that there is no suspicion of overcorrection, or the like.

[0109] As described above, in the red-green test of the subject's eye E in this embodiment, the reference image 120 is acquired when the subject's eye E is corrected with a predetermined spherical power, and whether or not the subject's eye E is in an overcorrected state is detected based on the reference image 120, and the overcorrection information 223 is output based on the detection result. For example, the control unit 70 may acquire a reference image, detect an overcorrected state, and output the overcorrection information 223 based on the reference image, each time the spherical power is changed while the red-green test is being performed. For example, at this time, the reference image 120 and the calculation result 222 of the pupil diameter P2 may be updated sequentially on the operation screen 200. For example, the examiner can take appropriate measures to release the overcorrected state of the subject's eye E by checking the overcorrection information 223. As an example, the examiner may change the current correction power for correcting the subject's eye E by one step to the positive side (i.e., add +0.50D to the current correction power).

[0110] The examiner may check the overcorrection information output after changing the correction power of the subject's eye E, and if the overcorrection state of the subject's eye E is not released, may repeatedly change the correction power by one step to the plus side. For example, the examiner may add fog to the subject's eye E.

[0111] The examiner performs the red-green test on the subject's eye E while checking the overcorrected state of the subject's eye E to obtain an appropriate spherical power for the subject's eye E. Next, the examiner performs the cross cylinder test and the visual acuity test on the subject's eye E in sequence. For example, in the cross cylinder test and the visual acuity test on the subject's eye E, it may be possible to similarly detect whether the subject's eye E is in an overcorrected state.

[0112] As described above, for example, the subjective eye examination device of this embodiment includes an anterior eye image acquisition means for acquiring an anterior eye image of the subject's eye during subjective measurement, an overcorrection detection means for detecting whether the subject's eye is in an overcorrected state based on the anterior eye image acquired by the anterior eye image acquisition means, and an operation control means for controlling an operation to release the overcorrected state of the subject's eye based on the detection result detected by the overcorrection detection means. This allows an appropriate response to be taken for the subject's eye, making it possible to prevent the subject's eye from becoming overcorrected, and therefore making it possible to correctly acquire the measurement result of the subject's eye.

[0113] Also, for example, in the subjective optometry device of this embodiment, the operation control means outputs overcorrection information for identifying that the subject's eye is in an overcorrected state as an operation for releasing the overcorrected state of the subject's eye. This allows the examiner to easily determine whether the subject's eye is in an overcorrected state or not, and to take appropriate measures to release the overcorrected state of the subject's eye. Therefore, the measurement result of the subject's eye can be correctly obtained.

[0114] <Example of transformation> In this embodiment, a configuration has been described in which the reference image 110 of the subject's eye E is obtained by capturing an anterior eye image of the subject, but the present invention is not limited to this. For example, a general template image of the anterior eye may be used as the reference image 110. As an example, an anterior eye image having average human pupil information (here, pupil diameter) may be used as the template image.

[0115] In addition, in detecting the overcorrected state of the subject's eye E, the reference image 110 is not necessarily required, and pupil information that serves as a criterion for determining the overcorrected state of the subject's eye E may be sufficient. For example, the average human pupil diameter may be stored in advance in the memory 75 as the reference pupil diameter. Alternatively, for example, the reference pupil diameter may be obtained from an experiment or a simulation and stored in advance in the memory 75. In this case, by comparing the reference pupil diameter with the pupil diameter P2 based on the reference image 120, it is possible to detect whether the subject's eye E is in an overcorrected state or not.

[0116] For example, in a configuration in which a template image is used as the reference image 110 of the subject's eye E and in which a reference pupil diameter is obtained in advance, it is not necessary to obtain an anterior eye image before starting subjective measurement of the subject's eye. Therefore, the examination of the subject's eye E can be smoothly carried out.

[0117] In this embodiment, the configuration in which an anterior eye image captured before the subjective measurement of the subject's eye E is started is used as the reference image 110 of the subject's eye E, but the present invention is not limited to this. For example, the reference image 110 of the subject's eye E may use an anterior eye image captured at a timing before the objective measurement of the subject's eye E is started, at any timing between the start and end of the objective measurement, or at a timing after the objective measurement is completed. For example, the reference image 110 of the subject's eye E may use an anterior eye image captured at any timing between the start and end of the subjective measurement of the subject's eye E. As an example, an anterior eye image captured at a timing immediately before the correction power for correcting the subject's eye E is changed may be used. In this case, the reference image 110 may be updated sequentially. As an example, an appropriate anterior eye image may be selected and used as the reference image 110 from among a plurality of reference images 120. In this case, among the multiple reference images 120, an anterior eye image having the largest pupil information (here, pupil diameter) may be used as the reference image 110. Also, among the multiple reference images 120, an anterior eye image having the most similar pupil information may be used as the reference image 110.

[0118] In this embodiment, a configuration for detecting a change in the pupil diameter of the subject's eye E using one standard image 110 and one reference image 120 has been described as an example, but the present invention is not limited to this. For example, a plurality of standard images 110 may be photographed at the same time, and an average value of the pupil diameter P1 may be taken. Similarly, for example, a plurality of reference images 120 may be photographed at the same time, and an average value of the pupil diameter P2 may be taken. For example, the subject's eye E is constantly changing its pupil, and the pupil diameter fluctuates. In particular, the pupil diameter may fluctuate significantly with the miosis of the subject's eye E. For this reason, by taking the average value of the pupil diameter based on the plurality of standard images 110 and the reference image 120, it is possible to detect whether or not the eye is overcorrected with greater accuracy. In addition, the fluctuation of the pupil diameter may be detected from an anterior eye image of the subject's eye E, and the standard image 110 and the reference image 120 may be captured when the fluctuation is equal to or less than a predetermined threshold value, and the pupil diameter is considered to be stable.

[0119] In the present embodiment, a configuration in which an anterior eye image (reference image 120) is acquired each time the correction power of the subject's eye E is changed in the subjective measurement of the subject's eye E has been described as an example, but the present invention is not limited thereto. For example, in the subjective measurement of the subject's eye E, a configuration in which the reference image 120 of the subject's eye E is continuously acquired at a predetermined frame rate (e.g., 30 fps) may be used. For example, by setting a small frame rate, the reference image 120 can be acquired in more real time, and it is possible to detect whether the eye is in an overcorrected state or not. In this case, the control unit 70 may sequentially store each reference image (first reference image, second reference image, ..., nth reference image) of the subject's eye E in the memory 75 in association with the elapsed time of the subjective test.

[0120] When the reference image 110 of the subject's eye E is associated with the time course of the subjective measurement as described above, it is possible to represent as a graph the change over time of overcorrection information for identifying that the subject's eye E is in an overcorrected state. As an example, the overcorrection information may be pupil diameter, and the change over time of pupil diameter can be represented as a graph.

[0121] FIG. 12 is an example of a graph showing the change over time of the overcorrection information. FIG. 12(a) is an example showing the time elapsed in the subjective test on the horizontal axis. FIG. 12(b) is an example showing the correction power of the subject's eye E on the horizontal axis. The vertical axis of the graph is the pupil diameter of the subject's eye E. For example, when the control unit 70 finishes the subjective test of the subject's eye E (here, the red-green test), the control unit 70 may create a graph 230 in which the pupil diameter P2 based on the successive reference images 120 of the subject's eye E is plotted against the elapsed time of the subjective test. For example, in addition to the plot of each pupil diameter P2, the graph 230 may also have an approximation line 130 (for example, a moving average line, etc.) for the change in the pupil diameter P2 drawn. For example, the control unit 70 may display such a graph 230 on the operation screen 200.

[0122] Here, in the subjective examination of the subject's eye E, when an anterior eye image (reference image 120) is acquired every time the correction power for correcting the subject's eye E is changed, each reference image and the correction power are associated with each other and stored, so that the horizontal axis of the graph can be represented by the correction power. For example, when the subjective examination (red-green examination) of the subject's eye E is completed, the control unit 70 may create a graph 240 in which the pupil diameter P2 based on the successive reference images 120 of the subject's eye E is plotted against the change in the correction power (spherical power). For example, the approximation line 130 may be drawn in the graph 240 as in the graph 230. For example, the control unit 70 may display such a graph 240 on the operation screen 200.

[0123] In addition, in the graph showing the change in pupil diameter over time as described above, the relationship may be shown between the elapsed time of the subjective test, the timing at which the corrective power of the subject's eye E is changed, and the pupil diameter P2 of the subject's eye E. As an example, a two-axis graph may be created in which the elapsed time of the subjective test is on the horizontal axis, the pupil diameter P2 of the subject's eye E is on the first vertical axis, and the corrective power of the subject's eye E is on the second vertical axis.

[0124] Furthermore, the graph showing the change in pupil diameter over time as described above may be created in real time during subjective measurement, rather than after subjective measurement of the subject's eye E. In this case, the pupil diameter P2 may be calculated every time the reference image 120 of the subject's eye E is acquired, and the calculated value may be plotted on the graph to form the graph.

[0125] In this way, for example, in the subjective ophthalmology device of this embodiment, the anterior eye image acquisition means continuously acquires anterior eye images at a predetermined timing during subjective measurement, and the operation control means outputs a graph showing the change in overcorrection information over time based on the anterior eye images continuously acquired by the anterior eye image acquisition means. For example, by checking such a graph, the examiner can easily determine at what timing the subject's eye became overcorrected during subjective measurement. In addition, the examiner can take measures such as releasing the overcorrection state of the subject's eye or restarting the subjective measurement from the beginning or halfway through, as necessary.

[0126] In addition, for example, in the subjective eye examination device of this embodiment, the predetermined timing for continuously acquiring anterior eye images is the timing each time the optical characteristics of the visual target light beam are changed by the correction means. For example, by acquiring anterior eye images at the timing when the correction power for correcting the examined eye is changed, the examiner can easily determine the correction power at which the examined eye is in an overcorrected state.

[0127] In this embodiment, a configuration has been described in which overcorrection information for identifying an overcorrection state is output each time an overcorrection state of the subject's eye E is detected, but the present invention is not limited to this. For example, a configuration may be used in which overcorrection information is output when an overcorrection state of the subject's eye E is detected more than a predetermined number of times. For example, the predetermined number of times may be a number of times (e.g., three times) set based on an experiment or simulation. In addition, for example, a configuration may be used in which, after subjective measurement of the subject's eye E is completed, the presence or absence of detection of an overcorrection state, the number of times an overcorrection state has been detected, and the like are output together with the subjective measurement result.

[0128] In this embodiment, as an example of an operation for releasing the overcorrection state of the subject's eye E, a configuration has been described in which overcorrection information is output and the examiner takes appropriate action based on the overcorrection information to release the overcorrection state, but the present invention is not limited thereto. For example, the overcorrection state may be released by automatically executing an operation for releasing the overcorrection state of the subject's eye E. As an example, the current first correction power for correcting the subject's eye E may be automatically changed to a second correction power that is stronger on the positive side than the first correction power.

[0129] Here, in the red-green test of the subject's eye E, the subject's eye E is corrected with a spherical power (first spherical power) of -3.00D. For example, when the control unit 70 detects that the subject's eye E is in an overcorrected state (step S4 in FIG. 9: YES), the control unit 70 controls the light projection optical system 30 based on such a detection signal to move the display 31 in the optical axis direction. For example, the control unit 70 moves the display 31 in the optical axis direction so as to change the current first spherical power of the subject's eye E by one step and add +0.25D. For example, this causes the subject's eye E to be corrected with a second spherical power of -2.75D, making it easier to release the overcorrected state. Of course, the change from the first spherical power to the second spherical power may be one or more steps.

[0130] The control unit 70 may add a predetermined amount of fogging by changing the eye E from the first spherical power to the second spherical power. For example, when the control unit 70 detects that the eye E is in an overcorrected state (step S4 in FIG. 9: YES), the control unit 70 controls the light projection optical system 30 based on such a detection signal to move the display 31 in the optical axis direction. For example, the control unit 70 moves the display 31 in the optical axis direction so as to add a predetermined amount of fogging to the eye E. As an example, the display 31 may be moved by a spherical power of -2.25D so as to add an amount of fogging that makes the visual acuity of the eye E about 0.7. This causes the test target to be visually recognized as blurred by the eye E, and the adjustment is released, which results in the overcorrected state being easily released. The amount of fogging of the eye E may be set in advance by an experiment or a simulation. In this case, a different amount of fogging may be set according to the correction power of the eye E.

[0131] In this way, for example, in the subjective eye examination device of this embodiment, the operation control means controls the correction means as an operation for releasing the overcorrection state of the subject's eye, and changes the current first correction power for correcting the subject's eye to a second correction power that is stronger on the positive side than the first correction power. For example, by weakening the correction power of the subject's eye, the thickness of the crystalline lens of the subject's eye changes and accommodation is easily released, resulting in the overcorrection state being easily released. In addition, by releasing the overcorrection state of the subject's eye, subjective measurement of the subject's eye can be performed smoothly.

[0132] In this embodiment, when miosis is observed in the subject's eye E, the subject's eye E is deemed to be in an overcorrected state, and an operation to release this state is executed, but the present invention is not limited to this. For example, when miosis is observed in the subject's eye E, the brightness of the display 31 may be adjusted so that the miosis of the subject's eye E is released and the pupil diameter returns to a predetermined value.

[0133] For example, the appearance of the test target changes when the subject's eye E is in a normal state and when the subject's eye E is in a contracted state. For example, when the subject's eye E contracts, the focal depth changes, and the range in the front-back direction in which the image appears to be in focus becomes wider. This causes the condition when the subject's eye E sees the test target to change, and there is a possibility that correct test results cannot be obtained. However, for example, by changing the brightness of the display 31 according to the amount of change in the pupil diameter of the subject's eye E, each test can be progressed while keeping the pupil diameter of the subject's eye E constant. For example, the amount of change in the brightness of the display 31 relative to the amount of change in the pupil diameter may be set in advance by experiment or simulation. This allows correct test results of the subject's eye to be obtained.

[0134] In this embodiment, the optometry apparatus is described as an example of an apparatus that can perform subjective measurement without placing an optical member or the like in front of the eye E and with the eye E open, but is not limited thereto. For example, the optometry apparatus may be an apparatus that is placed in front of the eye E and includes an eye refractive power measurement unit having a correction optical system therein. In this case, the eye refractive power measurement unit may be provided with an imaging unit for imaging the anterior segment of the eye E. For example, the optometry apparatus may be an apparatus that is separately provided with a visual target presenting device as described in JP 2012-90956 A. In this case, the visual target presenting device may be provided with an imaging unit. For example, the optometry apparatus may be a visual acuity testing apparatus as described in JP 2005-52677 A, and the visual acuity testing apparatus may be configured to include an imaging unit. That is, in this embodiment, the optometry apparatus may be provided with a configuration that can acquire an image of the anterior segment of the eye E. [Explanation of symbols]

[0135] 2. Cabinet 6 Controller 7 Measuring part 10 Objective Measuring Optical System 25 Subjective Measuring Optical System 30 Projection optical system 40 Alignment Optical System 50 Observation Optical System 60 Corrective optical system 70 Control section 75 Memory 90 Imaging section 100 Optometry equipment

Claims

1. a corrective means arranged in an optical path of a light projection optical system that projects a visual target light beam toward the subject's eye, and that changes the optical characteristics of the visual target light beam; A subjective ophthalmological examination device that subjectively measures optical characteristics of the subject's eye, an anterior ocular segment image acquiring means for acquiring an anterior ocular segment image of the subject's eye during subjective measurement; an overcorrection detection means for detecting whether the subject's eye is in an overcorrected state based on the anterior eye image acquired by the anterior eye image acquisition means; an operation control means for controlling an operation for canceling the overcorrection state of the subject's eye based on the detection result detected by the overcorrection detection means; A subjective ophthalmological examination device comprising:

2. The subjective ophthalmological examination device of claim 1, The operation control means controls the correction means as an operation to release the overcorrected state of the subject's eye, and changes the current first correction power for correcting the subject's eye to a second correction power that is stronger on the positive side than the first correction power.

3. The subjective ophthalmological examination device according to claim 1 or 2, The subjective ophthalmological examination device is characterized in that the operation control means outputs overcorrection information for identifying that the subject's eye is in the overcorrection state as an operation to release the overcorrection state of the subject's eye.

4. The subjective ophthalmological examination device according to claim 3, the anterior eye image acquisition means continuously acquires the anterior eye image at a predetermined timing during subjective measurement, The subjective ophthalmological examination device is characterized in that the operation control means outputs a graph showing changes in the overcorrection information over time based on the anterior segment images continuously acquired by the anterior segment image acquisition means.

5. A corrective means is disposed in the optical path of a light projection optical system that projects a visual target light beam toward the subject's eye, and that changes the optical characteristics of the visual target light beam; A subjective optometry program used in a subjective optometry device that subjectively measures optical characteristics of the subject's eye, an anterior ocular segment image acquiring step of acquiring an anterior ocular segment image of the subject's eye during subjective measurement; an overcorrection detection step of detecting whether the subject's eye is in an overcorrected state based on the anterior eye image acquired in the anterior eye image acquisition step; an operation control step of controlling an operation for canceling the overcorrection state of the subject's eye based on the detection result detected in the overcorrection detection step; A subjective optometry program that causes the subjective optometry device to execute the above.

Images