Ophthalmic examination device and ophthalmic examination method

Abstract

Provided is an ophthalmic examination device with which it is possible to acquire complex information that is required in a preliminary examination for corrective prescription when determining which of right and left eyes is a dominant eye. An ophthalmic examination device (100) is for performing an examination by projecting visual targets onto each of left and right eyes EL and ER to be examined, and includes a visual target projection system (4) and a control unit (140). The visual target projection system (4) projects, as visual targets, at least a pair of visual targets that are partially different in form or are recognized to be partially different in form. When performing a dominant eye examination by binocular vision, the control unit (140) switches examination conditions corresponding to influencing elements that affect the result of the dominant eye determination and controls various optical systems and visual target presentation according to the examination conditions.

Description

Ophthalmic examination device and ophthalmic examination method

[0001] The present disclosure relates to an ophthalmic examination apparatus and an ophthalmic examination method.

[0002] Prior art related to determining the dominant eye includes the techniques described in Non-Patent Document 1 and Patent Document 1. Non-Patent Document 1 describes test methods for determining the dominant eye and ocular dominance. Test methods include, for example, the hole-in-a-card test, the pointing test, the kaleidoscope test, the convergence near point test, the plus 1D test, the Worth test, the polarization test, the distance stereo test, and the Heidinger test.

[0003] Patent Document 1 describes an ocular dominance quantification device that can quantitatively measure ocular dominance and reliably identify the dominant eye. The ocular dominance quantification device increases or decreases the contrast of a symmetrical striped binocular rivalry stimulus figure, and when it determines that the perceived interval of the binocular rivalry stimulus figure in binocular vision has become equal, it measures the contrast ratio of the binocular rivalry stimulus figure at that point.

[0004] Here, the "dominant eye" refers to the eye that receives information that the brain recognizes predominantly when looking at something with both eyes open, and the other eye is called the non-dominant eye. "Ocular dominance" refers to the difference between the degree to which the brain recognizes information through the dominant eye and the non-dominant eye. Strong ocular dominance refers to a large difference in the degree to which the brain recognizes information between the dominant eye and the non-dominant eye. Weak ocular dominance refers to a small difference in the degree to which the brain recognizes information between the dominant eye and the non-dominant eye.

[0005] “Ocular dominance diagnosis and its influence in monovision.” American Journal of Ophthalmology 144.2 (2007): 209-216

[0006] JP 2010-264281 A

[0007] In cataract surgery, for example, after the clouding of the crystalline lens is removed, an intraocular lens (IOL, an abbreviation for "Intra Ocular Lens") is inserted according to a monovision prescription. Here, "monovision prescription" refers to a corrective prescription that focuses the dominant eye on distant objects and the non-dominant eye on intermediate to near objects, making it easier to see both far and near objects when using both eyes.

[0008] In addition to the monovision prescription, other corrective prescriptions include micromonovision prescriptions, which slightly shift the corrective refractive power of the dominant eye and the non-dominant eye within a comfortable range. Another known prescription involves implanting an intraocular contact lens (ICL, an abbreviation for "Implantable Contact Lens") to correct refractive errors (myopia, hyperopia, and astigmatism) and restore unaided visual acuity. Another known corrective prescription involves prescribing bifocal multifocal contact lenses. Therefore, before administering these various corrective prescriptions, a preliminary examination is required to determine which eye is the dominant eye.

[0009] However, if the pre-examination only determines which eye is dominant, it is not possible to provide an appropriate correction prescription tailored to the individual eye characteristics of each subject. For this reason, the pre-examination must obtain information on the dominant and non-dominant eyes, as well as comprehensive information including the degree of ocular dominance, the effects of the test distance and refractive power, etc.

[0010] For example, with regard to monovision prescriptions, it is known that "when a multifocal intraocular lens that is prone to producing glare is prescribed for the non-dominant eye and a monofocal intraocular lens that is less likely to produce glare is prescribed for the dominant eye, there are cases in which the glare is bothersome and cases in which the glare is not bothersome." In cases in which the glare generated in the non-dominant eye is not bothersome, it is thought that this is because the ocular dominance is strong and the patient sees an image without glare, as shown in Figure 6A. On the other hand, in cases in which the glare generated in the non-dominant eye is bothersome, it is thought that this is because the ocular dominance is weak and the patient sees an image with glare, as shown in Figure 6B.

[0011] Furthermore, it is known that the determination of the dominant eye and the degree of ocular dominance are affected by whether the test distance to the visual target is far or close, and that the determination of the dominant eye and the degree of ocular dominance are also affected by whether the refractive power of both eyes is the uncorrected refractive power or the corrected refractive power.

[0012] Therefore, when prescribing correction, there is a demand for comprehensive information, including information on the dominant and non-dominant eyes, the degree of ocular dominance, the effects of the examination distance and refractive power, to be known through a pre-examination.

[0013] In contrast, the prior art does not disclose the acquisition of complex information required in a pre-examination of a correction prescription in either Non-Patent Document 1 or Patent Document 1. Therefore, when the prior art is applied to a pre-examination of a correction prescription, it is not possible to obtain an appropriate correction prescription that is tailored to the individual eye characteristics that differ for each subject.

[0014] The present disclosure has been made with a focus on the above-mentioned problems, and aims to provide an ophthalmic examination device and an ophthalmic examination method that can acquire the complex information required in the pre-examination of a corrective prescription when determining which of the left and right eyes is the dominant eye.

[0015] The ophthalmic examination apparatus disclosed herein is an apparatus for projecting a visual target onto each of the left and right eyes to be examined, and includes a visual target projection system and a control unit. The visual target projection system projects at least a pair of visual targets that are partially different in shape or that are recognized as being partially different in shape as the visual targets. When conducting a dominant eye test using binocular vision, the control unit switches test conditions corresponding to influencing factors that affect the determination result of the dominant eye, and controls various optical systems and visual target presentation according to the test conditions.

[0016] The ophthalmologic examination method disclosed herein is a method for projecting a visual target onto each of the left and right eyes to be examined and includes an examination condition switching step, a visual target presenting step, and a dominant eye test implementation step. The examination condition switching step switches examination conditions corresponding to influencing factors that affect the determination result when determining the dominant eye from the left and right eyes to be examined. The visual target presenting step projects and presents a pair of visual targets that are partially different in shape or are recognized as being partially different in shape to the left and right eyes, respectively. The dominant eye test implementation step presents the pair of visual targets in a visual target presentation pattern according to the examination conditions, and implements a dominant eye test using binocular vision.

[0017] The ophthalmic examination apparatus and ophthalmic examination method according to the present disclosure can obtain the complex information required in the pre-examination of a correction prescription when determining which of the left and right eyes is the dominant eye.

[0018] 1 is a perspective view showing the appearance of an ophthalmic examination apparatus. FIG. 2 is a development view showing the configuration of a left eye measurement optical system provided in the ophthalmic examination apparatus. FIG. 3 is a block diagram showing the configuration of an electronic control system provided in the ophthalmic examination apparatus. FIG. 4 is a view showing pattern A of optotypes for a color dot test in embodiment 1. FIG. 5 is a view showing pattern B of optotypes for a color dot test in embodiment 1. FIG. 6 is a flowchart showing an example of a dominant eye determination operation in embodiment 1. FIG. 7 is a view showing an image of driving at night when there is no glare. FIG. 8 is a view showing an image of driving at night when there is glare. FIG. 9 is a result table showing an example of test results from a color dot test. FIG. 10 is a view showing pattern A of a first optotype pair in embodiment 2. FIG. 11 is a view showing pattern A of a second optotype pair in embodiment 2. FIG. 12 is a view showing pattern A of a third optotype pair in embodiment 2. FIG. 13 is a flowchart showing an example of a dominant eye determination operation in embodiment 2. FIG. 14 is a result table showing an example of test results from a glare test. FIG. 15 is a view showing pattern A of optotypes for a binocular rivalry test in embodiment 3. FIG. 16 is a view showing pattern B of optotypes for a binocular rivalry test in embodiment 3. FIG. 17 is a flowchart showing an example of a dominant eye determination operation in embodiment 3. FIG. 18 is a result table showing an example of test results from a binocular rivalry test. FIG. 19 is a view showing an example of optotypes that are the same but are recognized as having partially different shapes.

[0019] The ophthalmic examination apparatus and the ophthalmic examination method according to the present disclosure will be described as embodiments 1 to 3 with reference to the drawings.

[0020] The ophthalmic examination apparatus applied to Embodiments 1 to 3 is a binocular open-type apparatus that can simultaneously measure the ocular characteristics of both eyes while the subject keeps both eyes open. This ophthalmic examination apparatus can also measure the ocular characteristics of one eye at a time by blocking one eye or turning off the fixation target. This ophthalmic examination apparatus is an objective measurement device with a subjective test function that includes a target presentation function, a phoropter function, and an autorefractive / keratometric measurement function. In other words, the examiner can use a single ophthalmic examination apparatus to perform both a subjective test to obtain information such as the visual acuity of the subject's eye and an objective measurement to obtain information such as the refractive power of the subject's eye.

[0021] Here, objective measurement refers to measurement that obtains objective measurement information without requiring a response from the subject, and includes photography that obtains a fundus image of the subject's eye, etc. Objective measurements include refractive power measurement (refractometry), corneal shape measurement (keratometry), intraocular pressure measurement, fundus photography, fundus tomography using optical coherence tomography (OCT photography), and measurement using OCT. Note that "OCT" is an abbreviation for "Optical Coherence Tomography."

[0022] A subjective test is a test in which the subject answers questions about the content of optotypes seen in the left and right eyes. Subjective tests include a distance test, an intermediate distance test, a near test, a contrast test, a glare test, a visual field test, etc. (Embodiment 1)

[0023] [Overall Configuration of the Apparatus (Fig. 1)] The overall configuration of the ophthalmic examination apparatus 100 will be described with reference to Fig. 1, which shows the external appearance of the ophthalmic examination apparatus 100. Note that the X, Y, and Z axes used in the drawings and description are such that, when viewed from the subject, the horizontal axis in the left-right direction is the X axis, the vertical axis in the up-down direction is the Y axis, and the front-to-back axis in the depth direction, which is perpendicular to the X and Y axes, is the Z axis.

[0024] As shown in FIG. 1 , the ophthalmic examination apparatus 100 includes a support base 110 , a measurement unit 120 , an examiner's controller 130 , and a control unit 140 .

[0025] The support base 110 has a support column 111 standing up from the floor surface and an optometry table 112 supported by the support column 111. The optometry table 112 is a platform on which devices and tools used in the optometry examination, such as the examiner controller 130, are placed and which supports the posture of the subject. The position (height position) of the optometry table 112 in the Y-axis direction may be fixed, or the position (height position) of the optometry table 112 may be supported by the support column 111 so that the position (height position) in the Y-axis direction is adjustable.

[0026] The measurement unit 120 includes an arm 121, a drive base 122, a left eye measurement head 123L, and a right eye measurement head 123R. The measurement unit 120 also includes a left eye drive unit 124L, a right eye drive unit 124R, a left eye measurement optical system 125L, a right eye measurement optical system 125R, and a forehead support 126.

[0027] The arm 121 is a member having one end supported by the tip of the support 111 and the other end extending from the support 111 to the near side (subject side) along the Z direction, with a drive base 122 attached to the tip. The arm 121 is also movable in the Y-axis direction relative to the support 111.

[0028] The drive base 122 is attached to the tip of the arm 121. The drive base 122 incorporates a left eye drive unit 124L that drives the left eye measurement head 123L and a right eye drive unit 124R that drives the right eye measurement head 123R.

[0029] The left eye measurement head unit 123L and the right eye measurement head unit 123R are arranged as a pair on the left and right sides below the drive base unit 122 and are supported in a suspended state by the drive base unit 122. The left eye measurement head unit 123L and the right eye measurement head unit 123R are arranged at left and right positions separated in the X-axis direction, and a forehead rest 126 is provided in the opposing space between the left eye measurement head unit 123L and the right eye measurement head unit 123R. In other words, the left eye measurement head unit 123L and the right eye measurement head unit 123R correspond to the left and right eyes of the subject, respectively.

[0030] The left eye driver 124L is a mechanism that drives the left eye measurement head 123L to move in the X-axis direction, move in the Y-axis direction, rotate around the X-axis, and rotate around the Y-axis. The right eye driver 124R is a mechanism that drives the right eye measurement head 123R to move in the X-axis direction, move in the Y-axis direction, rotate around the X-axis, and rotate around the Y-axis. In other words, the left eye driver 124L and the right eye driver 124R individually drive the left eye measurement head 123L and the right eye measurement head 123R.

[0031] The left eye measurement head unit 123L has a built-in left eye measurement optical system 125L. The left eye measurement optical system 125L presents a visual target to the subject's left eye and measures the ocular characteristics of the left eye with the spherical power (corrected power) set to an arbitrary value. The right eye measurement head unit 123R has a built-in right eye measurement optical system 125R. The right eye measurement optical system 125R presents a visual target to the subject's right eye and measures the ocular characteristics of the right eye with the spherical power (corrected power) set to an arbitrary value. The detailed configurations of the left eye measurement optical system 125L and the right eye measurement optical system 125R will be described in detail in the "Configuration of the Optical System" section below.

[0032] The forehead rest 126 is provided in the measurement unit 120 and is disposed between the left eye measurement head 123L and the right eye measurement head 123R. The forehead rest 126 supports the subject's face by contacting a part of the subject's face (forehead) during subjective and objective measurements of eye characteristics. That is, the subject facing the ophthalmological examination table 112 presses their forehead against the forehead rest 126 to stabilize the face and prevent movement in orientation or position. The height position of the forehead rest 126 is adjusted by moving the arm 121 in the Y-axis direction relative to the support 111. Note that the face support member for the subject may include a cheek rest in addition to the forehead rest 126.

[0033] The examiner's controller 130 is an information processing device that accepts input operations by the examiner and outputs control signals to the control unit 140. The examiner's controller 130 is, for example, a tablet terminal or the like, which is separated from the measurement unit 120 and can be carried by the examiner. The examiner's controller 130 may be a notebook personal computer, a desktop personal computer, or a dedicated controller provided in the ophthalmic examination apparatus 100. The examiner's controller 130 exchanges information with the control unit 140 via a cable, wireless communication, or network communication.

[0034] As shown in Fig. 1, the examiner's controller 130 includes a display unit 131 and an operation-side control unit (not shown). The display unit 131 is made up of a touch panel display provided on the surface of the examiner's controller 130, and input buttons 132 (see Fig. 3) and the like are set by screen display. The operation-side control unit is made up of a microcomputer built into the examiner's controller 130. The operation-side control unit controls images displayed on the display unit 131 based on measurement results and detection results transmitted from the control unit 140. The operation-side control unit also outputs control signals to the control unit 140 in response to operations on the displayed input buttons 132 and the like.

[0035] [Configuration of Optical System (FIG. 2)] The configuration of the optical system will be described with reference to FIG. 2, which shows the configuration of the left eye measurement optical system 125L provided in the ophthalmic examination apparatus 100. Since the left eye measurement optical system 125L and the right eye measurement optical system 125R have the same configuration, the illustration and description of the right eye measurement optical system 125R will be omitted. Furthermore, the "fundus conjugate position P" used in the following description is a position that is approximately optically conjugate with the fundus ELf of the left eye EL when alignment is complete, and refers to a position that is optically conjugate with the fundus ELf of the left eye EL or its vicinity. The "pupil conjugate position Q" is a position that is approximately optically conjugate with the pupil of the left eye EL when alignment is complete, and refers to a position that is optically conjugate with the pupil of the left eye EL or its vicinity.

[0036] The left eye measurement optical system 125L is an optical system that performs an examination by presenting a visual target to the left eye EL. As shown in Figure 2, the left eye measurement optical system 125L includes a Z alignment system 1, an XY alignment system 2, a keratomileusis measurement system 3, a visual target projection system 4, an anterior eye observation system 5, a reflex measurement projection system 6, and a reflex measurement light-receiving system 7.

[0037] The Z alignment system 1 projects light (infrared light) onto the left eye EL to align the anterior segment observation system 5 in the optical axis direction (Z axis direction). The light output from the two Z alignment light sources 11 is converted into parallel beams by the projection lens 12 and projected onto the cornea of ​​the left eye EL through an alignment hole formed in the keratoplasty plate 31. The control unit 140 or the examiner controls the drive unit 122a based on the bright spot projected onto the cornea to move the left eye measurement optical system 125L in the Z axis direction. This Z axis alignment is achieved by controlling the drive unit 122a so that the ratio between the distance between two bright spot images generated by the Z alignment light source 11 on the image sensor 59 and the diameter of a keratoplasty image (described later) falls within a predetermined range.

[0038] The XY alignment system 2 irradiates the left eye EL with light (infrared light) that performs alignment in the X-axis and Y-axis directions perpendicular to the optical axis (Z-axis) of the anterior-segment observation system 5. The XY alignment system 2 includes an XY alignment light source 21 and a projection lens 22, which are provided on an optical path branched from the anterior-segment observation system 5 by a half mirror 54. The light output from the XY alignment light source 21 passes through the projection lens 22, is reflected by the half mirror 54, and is projected onto the cornea of ​​the left eye EL via the anterior-segment observation system 5. The light reflected by the cornea of ​​the left eye EL is guided to an image sensor 59 via the anterior-segment observation system 5, thereby obtaining an image (bright spot image) based on the light reflected by the cornea.

[0039] Here, the image based on light reflected by the cornea (bright spot image) is included in the anterior segment image. The control unit 140 controls the display unit 131 to display the anterior segment image including the bright spot image and the alignment mark. When performing XY alignment manually, the examiner uses the examiner controller 130 to control the drive unit 122a to guide the bright spot image into the alignment mark and move the left eye measurement optical system 125L in the X-axis and Y-axis directions. When performing XY alignment automatically, the control unit 140 controls the drive unit 122a to cancel the displacement of the bright spot image relative to the alignment mark and move the left eye measurement optical system 125L in the X-axis and Y-axis directions. Note that the alignment method in each of the X, Y, and Z directions is not limited to the method using the Z alignment system 1 or the XY alignment system 2. For example, any method can be used that can measure the positions of the left eye EL and the right eye ER using a stereo camera installed in the left eye measurement optical system 125L and the right eye measurement optical system 125R so as to photograph the anterior segments of each eye from two directions.

[0040] The keratometry system 3 projects a ring-shaped light beam (infrared light) onto the cornea of ​​the left eye EL to measure the shape of the cornea. The keratometry plate 31 is disposed between the objective lens 52 and the left eye EL, and a keratometry light source 32 is provided on the back side (on the objective lens 52 side). The keratometry light source 32 illuminates the keratometry plate 31 with light from the back side, thereby projecting a ring-shaped light beam onto the cornea of ​​the left eye EL. The light reflected from the cornea of ​​the left eye EL (keratometry image) is detected by the image sensor 59 together with the anterior segment image. The control unit 140 calculates corneal shape parameters representing the shape of the cornea by performing known calculations based on the keratometry image.

[0041] The visual target projection system 4 presents various visual targets, such as fixation targets and visual targets for subjective testing, to the left eye EL. The visual target projection system 4 includes a display 41, a half mirror 42, a relay lens 43, a reflecting mirror 44, a focusing lens 45, a relay lens 46, a field lens 47, a variable cross cylinder lens 48, and a reflecting mirror 49. The variable cross cylinder lens 48 will be referred to as a VCC 48 hereinafter. The visual target projection system 4 shares a dichroic mirror 68 with the reflector measurement projection system 6. The visual target projection system 4 also shares a dichroic mirror 53 and an objective lens 52 with the anterior eye observation system 5. Furthermore, the visual target projection system 4 includes at least two glare light sources 41a that irradiate glare light onto the left eye EL, located around the optical axis on an optical path separate from the optical path leading to the display 41 that displays the left eye projected visual target.

[0042] Light output from the display 41 is reflected by the half mirror 42, passes through the relay lens 43, is reflected by the reflecting mirror 44, and passes through the focusing lens 45. The light that passes through the focusing lens 45 passes through the relay lens 46, has its direction of travel aligned by the field lens 47, passes through the VCC 48, is reflected by the reflecting mirror 49, passes through the dichroic mirror 68, and is reflected by the dichroic mirror 53. The light reflected by the dichroic mirror 53 passes through the objective lens 52 and enters the fundus ELf.

[0043] The display 41 displays a fixation target or a dot target as a target to fixate the gaze when performing objective measurement or when fogging the left eye EL, or a subjective test target for subjectively testing the eye characteristics of the left eye EL (visual acuity, distance vision power, near vision power, etc.). The display 41 uses a liquid crystal display, but an organic EL display or the like can also be used. The targets to be projected onto the left eye EL and the right eye ER can be arbitrarily created as still or moving images, and the created targets can be registered as selectable chart icons on a chart page. The display 41 can select and display a created still image target or a created moving image target from the chart page. The display 41 is provided at a fundus conjugate position P on the optical path of the target projection system 4.

[0044] The focusing lens 45 is driven forward and backward along the optical axis by a drive motor (not shown) controlled by the control unit 140. When the control unit 140 controls the focusing lens 45 to move toward the left eye EL, it changes the spherical power of the left eye EL to the negative diopter side (-D side) in the near vision direction. When the control unit 140 controls the focusing lens 45 to move away from the left eye EL, it changes the spherical power of the left eye EL to the positive diopter side (+D side) in the far vision direction. Furthermore, the control unit 140 controls the forward and backward driving of the focusing lens 45 to change the test distance from the left eye EL to the optotype presentation position. Here, the focusing lens 45, the reflective measurement light source 61, and the focusing lens 74 are configured to move in conjunction with each other.

[0045] When a subjective test is performed, the control unit 140 moves the focusing lens 45 in the optical axis direction based on the results of the objective measurement, controls the test distance and the spherical power of the left eye EL, and controls the astigmatism axis and astigmatism power using the VCC 48. The control unit 140 then displays a predetermined optotype selected by the examiner or the control unit 140 on the display 41. This causes the optotype to be presented to the subject at a predetermined test distance, relative to the left eye EL adjusted to a predetermined spherical power. When the subject responds subjectively to the optotype, the control unit 140 receives input of the response. For example, in the case of a visual acuity test, the examiner selects and presents the next optotype based on the subject's subjective response to a Landolt ring or the like, and the visual acuity value is determined by repeating this process.

[0046] The anterior segment observation system 5 observes and photographs the anterior segment of the left eye EL. The anterior segment illumination light source 51 irradiates the anterior segment of the left eye EL with illumination light (e.g., infrared light). The light reflected by the anterior segment of the left eye EL passes through the objective lens 52, the dichroic mirror 53, the half mirror 54, the relay lenses 55 and 56, and the dichroic mirror 57. The light transmitted through the dichroic mirror 57 is imaged on the imaging surface of the image sensor 59 by the imaging lens 58. The image sensor 59 captures images and outputs signals at a predetermined rate. The output (video signal) of the image sensor 59 is input to the control unit 140. The control unit 140 displays an anterior segment image (moving image) based on the video signal output from the image sensor 59 on the display unit 131 of the examiner's controller 130. The imaging surface of the image sensor 59 in the optical system of the anterior eye observation system 5 is disposed at the pupil conjugate position Q.

[0047] The refraction measurement projection system 6 and the refraction measurement light receiving system 7 are objective measurement optical systems used for objective refraction measurement (refraction measurement) to measure the objective refraction value as an ocular characteristic of the left eye EL. The refraction measurement projection system 6 projects a ring-shaped light beam (infrared light) for objective measurement from a refraction measurement light source 61 onto the fundus oculi ELf. The refraction measurement light receiving system 7 receives the return light of this ring-shaped light beam from the left eye EL.

[0048] The reflective measurement light source 61 may be an SLD light source, which is a high-brightness light source with an emission diameter of a predetermined size or less. SLD is an abbreviation for "Super luminescent Diode." The reflective measurement light source 61 is movable in the optical axis direction in conjunction with the focusing lens 45 and the focusing lens 74, and is disposed at a fundus conjugate position P. The ring diaphragm 65 (specifically, a light-transmitting portion) is disposed at a pupil conjugate position Q. The focusing lens 74 is movable in the optical axis direction in conjunction with the reflective measurement light source 61 and the focusing lens 45. The focusing lens 74 may be a known variable-focus lens whose focal position can be changed under the control of the control unit 140. The imaging surface of the image sensor 59 in the optical system of the reflective measurement light-receiving system 7 is disposed at a fundus conjugate position P.

[0049] Light output from the reflector measurement light source 61 passes through a relay lens 62 and is incident on the conical surface of a conical prism 63. The light that enters the conical surface is deflected and exits from the bottom surface of the conical prism 63. The light that exits from the bottom surface of the conical prism 63 passes through a field lens 64 and a ring-shaped light-transmitting portion formed in an aperture ring 65. The light that passes through the light-transmitting portion of the aperture ring 65 (a ring-shaped light beam) is reflected by the reflective surface of an aperture prism 66, passes through a rotary prism 67, and is reflected by a dichroic mirror 68. The light reflected by the dichroic mirror 68 is reflected by a dichroic mirror 53, passes through the objective lens 52, and is projected onto the left eye EL.

[0050] It is desirable that the conical prism 63 be placed as close as possible to the pupil conjugate position Q. The conical prism 63 may have a ring diaphragm 65 attached to its bottom surface facing the field lens 64, for example. In this case, for example, a light-shielding film is vapor-deposited on the bottom surface of the conical prism 63 so as to form a ring-shaped light-transmitting portion. Alternatively, the ring diaphragm 65 may be located on the conical surface side of the conical prism 63.

[0051] The field lens 64 may have a ring diaphragm 65 attached to the lens surface facing the left eye EL, for example. In this case, for example, a light-shielding film is vapor-deposited on the lens surface of the field lens 64 to form a ring-shaped light-transmitting portion. The reflex measurement projection system 6 may be configured without the field lens 64. The ring diaphragm 65 may be a diaphragm formed with a light-transmitting portion having a shape corresponding to a predetermined measurement pattern, and the light-transmitting portion may be formed in this diaphragm at a position eccentric to the optical axis of the reflex measurement projection system 6. The diaphragm may also have two or more light-transmitting portions. The rotary prism 67 is used to average the light intensity distribution of the ring-shaped light beam relative to the blood vessels and diseased areas of the fundus ELf and to reduce speckle noise caused by the light source.

[0052] The return light of the ring-shaped light beam incident on the fundus ELf passes through the objective lens 52 and is reflected by the dichroic mirror 53 and the dichroic mirror 68. The return light reflected by the dichroic mirror 68 passes through the rotary prism 67, passes through the hole in the aperture prism 66, passes through the relay lens 71, is reflected by the reflecting mirror 72, and passes through the relay lens 73 and the focusing lens 74. The light that passed through the focusing lens 74 is reflected by the reflecting mirror 75, is reflected by the dichroic mirror 57, and forms an image on the imaging surface of the image sensor 59 by the imaging lens 58.

[0053] [Configuration of Electronic Control System (FIG. 3)] The configuration of the electronic control system will be described with reference to FIG. 3, which shows the configuration of the electronic control system provided in the ophthalmic examination apparatus 100.

[0054] The control unit 140 calculates eye refractive power parameters by performing known calculations based on the output from the image sensor 59. The eye refractive power parameters include the refraction values ​​(refractive powers), spherical power, astigmatism power, and astigmatism axis angle of the left and right test eyes EL and ER. The control unit 140 controls the left-eye measurement optical system 125L and the right-eye measurement optical system 125R, which include the REF measurement projection system 6, the REF measurement light-receiving system 7, and the visual target projection system 4, based on control signals transmitted from the examiner controller 130. The control unit 140 also comprehensively controls each component of the measurement unit 120, including the left-eye drive unit 124L and the right-eye drive unit 124R. Furthermore, the control unit 140 transmits the measurement results of the eye characteristics of the left eye EL and the right eye ER measured by the left-eye measurement head unit 123L and the right-eye measurement head unit 123R to the examiner controller 130.

[0055] As shown in FIG. 3 , the control unit 140 includes a main control unit 141 and a storage unit 142 .

[0056] The main control unit 141 controls the light intensity of the Z alignment light source 11, the XY alignment light source 21, and the keratinizing light source 32, and controls their on / off switching. The main control unit 141 controls the on / off of the optotype displayed on the display 41 of the optotype projection system 4, and controls the switching of the optotype. The main control unit 141 controls the light intensity of the anterior eye illumination light source 51, and controls the on / off switching. The main control unit 141 controls the exposure time and detection sensitivity of the image sensor 59. The main control unit 141 controls the light intensity of the reflex measurement light source 61, and controls the on / off switching of the rotational movement. The main control unit 141 controls the rotation speed of the rotary prism 67, and controls the on / off switching of the rotational movement. The main control unit 141 controls the position of the relay lens 56 in the optical axis direction. The main control unit 141 also controls the movement of the focusing lens 45, the reflex measurement light source 61, and the focusing lens 74, moving them in the optical axis direction in unison. The main control unit 141 performs processing to write data to the storage unit 142 and processing to read data from the storage unit 142 .

[0057] The memory unit 142 stores various data. The data stored in the memory unit 142 includes measurement information obtained by the keratometry system 3, measurement information obtained by the REF measurement projection system 6 and the REF measurement light receiving system 7, image data acquired by the image sensor 59, and information about the subject's eye. The information about the subject's eye includes information about the subject, such as a patient ID and name, and information about the left and right subject's eyes EL and ER, such as identification information for the left eye EL and the right eye ER. The memory unit 142 may be used as a working memory for calculating the corneal shape parameters and the refractive values ​​of the left and right subject's eyes EL and ER. The memory unit 142 also stores various programs and data for operating the ophthalmic examination apparatus 100.

[0058] [Dominant Eye Test Using a Pair of Color Dot Test Optotypes (FIGS. 4A and 4B)] The optotypes for the dominant eye test are set on the display 41 of the optotype projection system 4, and are required to be at least a pair of optotypes that are partially different in form or that are perceived as being partially different in form. Here, "partially different in form" refers to a pair of optotypes presented to each eye that are partially different in color, brightness, letters, pictures, etc., when compared. "Perceived as being partially different in form" refers to an optotype that is the same optotype, but that can be made to appear different in the left and right test eyes EL and ER by using filters, polarized lenses, etc.

[0059] The ophthalmic examination apparatus 100 of the first embodiment provides a pair of color dot test optotypes 80, 81 on the display 41 of the optotype projection system 4. As shown in FIG. 4A , the pair of color dot test optotypes 80, 81 have six circular color dots arranged in a vertical row in the center of vertically elongated rectangular optotype frames 80a, 81a. The color dot test optotype 80 is, from top to bottom, a red dot 80b, a blue dot 80c, a green dot 80d, a red dot 80e, a green dot 80f, and a blue dot 80g. The color dot test optotype 81 is, from top to bottom, a blue dot 81b, a green dot 81c, a red dot 81d, a green dot 81e, a blue dot 81f, and a red dot 81g. Thus, the pair of color dot test optotypes 80, 81 are arranged in a corresponding relationship such that the two dots drawn at corresponding positions for the left eye EL and the right eye ER are different colors. As shown in Fig. 4A, a pair of color dot test optotypes 80, 81 is a pattern in which the color dot test optotype 80 is placed on the left eye and the color dot test optotype 81 is placed on the right eye, which is referred to as pattern A. As shown in Fig. 4B, a pair of color dot test optotypes 80, 81 is a left-right reversed pattern in which the color dot test optotype 81 is placed on the left eye and the color dot test optotype 80 is placed on the right eye, which is referred to as pattern B.

[0060] Here, the configuration of the pair of color dot test optotypes 80, 81 is basically arbitrary. However, it is preferable that they satisfy the following conditions: (1) All luminances are the same. (Reason): This is to eliminate differences in visibility. (2) The pair of colors is equal, and there is no bias to either the left or right. A pair of color dot test optotypes 80, 81 is said to be equal if the color combinations are, for example, two red-blue pairs, two blue-green pairs, and two green-red pairs. In other words, to avoid bias in the colors on the left and right, the red-blue pair appears twice, but they are arranged so that they are red-blue and blue-red. (Reason): Some people may have different sensitivities to different colors, and if there is a bias in the colors, the difference in sensitivity may bias the answers in the subjective test.

[0061] The dominant eye test uses a pair of color dot test optotypes 80, 81, which are optotypes for the dominant eye test and are registered as chart icons on the display 41 of the optotype projection system 4. The control unit 140 controls and processes the optical systems related to the dominant eye test, along with the visual acuity test, etc. When conducting a binocular dominant eye test, the control unit 140 switches the test conditions depending on factors that affect the dominant eye determination result, and controls the various optical systems and optotype presentation according to the test conditions. That is, the main control unit 141 included in the control unit 140 is responsible for controlling the switching of the various optical systems and the switching of the optotype presentation of the pair of color dot test optotypes 80, 81. The memory unit 142 included in the control unit 140 is responsible for storing processing programs related to dominant eye determination.

[0062] The dominant eye test is a test that involves at least one of a subjective test and an objective measurement, and both can be performed, rather than just one of the two. Here, the ophthalmic examination apparatus 100 is an objective measurement device with a subjective test function, and therefore offers the options of selecting only a subjective test, only an objective measurement, or both a subjective test and an objective measurement. In other words, the ophthalmic examination apparatus 100 allows selection from three dominant eye test modes: a subjective test mode, an objective measurement mode, and a subjective test & objective measurement mode.

[0063] In the case of a subjective test, the examiner inputs the examinee's response when looking at a presented optotype for a dominant eye test into the examiner controller 130, or the examinee himself inputs the response into the examiner controller 130, and the dominant eye is determined based on this response input. In the case of a subjective test, when determining the dominant eye, the proportion of the left eye EL that is the dominant eye and the proportion of the right eye ER that is the dominant eye are calculated based on the response input, and it is possible to automatically determine which of the left and right test eyes EL, ER is the dominant eye.

[0064] In the case of objective measurement, the dominant eye is determined based on the result output (= result parameters) of the objective measurement information. In the case of objective measurement, when determining the dominant eye, it is possible to automatically determine which of the left and right test eyes EL, ER is the dominant eye by detecting the line of sight, etc. Furthermore, in the case of objective measurement, the processing flow from the objective measurement through the output of the objective measurement result to the determination of the dominant eye is pre-programmed. This makes it possible to fully automate the process from the start of measurement to the output of the determination of the dominant eye in the case of objective measurement, without requiring operations such as inputting answers from the test subject.

[0065] The configuration of the control unit 140 related to the dominant eye test will be explained in detail by dividing it into an optotype presentation instruction unit, a test condition switching instruction unit, a test information acquisition unit, a dominant eye determination unit, and a determination result output instruction unit.

[0066] The optotype presentation instruction unit outputs to the display 41 of the optotype projection system 4 an instruction to present a pair of optotypes to be projected onto the left and right eyes EL and ER using an optotype content change pattern that changes the optotype content. The optotype content change pattern may change a previously prepared pair of optotypes that are partially different in shape to a left-right reversed pattern, or two pairs of optotypes that are partially different in shape may be prepared in advance and the two pairs of optotypes may be changed. The optotype presentation instruction unit of the first embodiment outputs to the display 41 of the optotype projection system 4 an instruction to present a pair of color dot test optotypes 80 and 81 to the left eye EL and the right eye ER using an optotype content change pattern that changes between a left-right normal pattern (pattern A) and a left-right reversed pattern (pattern B).

[0067] The examination condition switching instruction unit outputs a control instruction to the drive motor of the focusing lens 45 of the optotype projection system 4 and the drive motor of the VCC 48 to switch examination conditions depending on an influencing factor that affects the determination result when determining the dominant eye from the left and right eyes EL, ER to be examined. When the influencing factor is the examination distance from the positions of the left and right eyes EL, ER to the position of the optotype and the examination condition is an examination distance change condition that changes the examination distance including a far vision distance and a near vision distance, the examination condition switching unit outputs a control instruction to the drive motor of the focusing lens 45 and the drive motor of the VCC 48 to be examined. When the influencing factor is the refractive power of the left and right eyes EL, ER to be examined and the examination condition is an examination state change condition that changes between a non-corrected state and a corrected state, the examination condition switching unit outputs a control instruction to the drive motor of the focusing lens 45 and the drive motor of the VCC 48 to be examined. The examination condition switching instruction unit of the first embodiment sets the examination condition as an examination distance change condition, and outputs a control instruction to change the examination distance between a far vision distance (e.g., about 3 m to 6 m) and a near vision distance (e.g., about 25 cm to 40 cm).The examination condition switching instruction unit of the first embodiment sets the examination condition as a correction state change condition, and outputs a control instruction to change between a non-correction state and a full correction state (refractive power correction, astigmatism correction, reproduction of a monovision prescription, etc.).

[0068] The test distance can be changed to various desired distances by controlling the position of the focusing lens 45 in the target projection system 4. The test distance from the left eye EL and the test distance from the right eye ER can be set to different distances. For vision correction of myopia or hyperopia, a perfect correction state can be achieved by controlling the focusing lens 45 in the target projection system 4 to the -D side or +D side. For astigmatism correction, a perfect correction state can be achieved by correcting the astigmatism axis and astigmatism power using the VCC 48 in the target projection system 4 and controlling to eliminate astigmatism.

[0069] When a binocular vision dominant eye test is initiated, the test information acquisition unit performs standby control to maintain the optotype presentation state at the time of the test, and acquires test information necessary for dominant eye determination during standby control. The dominant eye test is initiated by presenting a pair of optotypes by selecting from a plurality of optotype presentation patterns that combine optotype content change patterns and test conditions, and viewing the presented pair of optotypes with both eyes. The test information acquisition unit of the first embodiment acquires test information necessary for dominant eye determination using a combination of subjective testing and objective measurement. The subjective testing is a test in which a pair of color dot test optotypes 80, 81 are viewed by the left and right test eyes EL, ER through single-view fusion, and the test information necessary for dominant eye determination in the subjective testing is response information obtained by manually inputting the subject's response regarding the color seen. The test information required for determining the dominant eye in the objective measurement is the line of sight information of the left and right test eyes EL, ER obtained by the objective measurement process during the dominant eye test, and the refractive power information of the left and right test eyes EL, ER.

[0070] Here, the line of sight information of the left and right test eyes EL, ER is calculated by detecting the pupil position of the moving anterior eye image from the image sensor 59 provided in the anterior eye observation system 5 and an image (bright spot image) based on the light reflected by the cornea. This calculated line of sight can obtain line of sight information toward the visual target based on time changes, and information can be obtained as to which of the left and right test eyes EL, ER is attempting to focus on the visual target. The refractive power information of the left and right test eyes EL, ER can obtain information as to which of the left and right test eyes EL, ER is attempting to focus on the visual target based on the time change characteristics of the refractive value obtained from the refractive measurement projection system 6 and the refractive measurement light receiving system 7.

[0071] The dominant eye determination unit determines which of the left and right test eyes EL and ER is the dominant eye based on the response information obtained through the subjective test. For example, if the response indicates that four to six of the six dots arranged vertically through fusion are the color of the target corresponding to the right eye ER, the dominant eye determination unit determines that the right eye ER is the dominant eye and the left eye EL is the non-dominant eye. Furthermore, if the response indicates that five or six of the dots are the color of the target corresponding to the right eye ER, the dominant eye determination unit can determine that the right eye ER has strong ocular dominance. In other words, the dominant eye determination unit can determine the dominant eye based on the relative size of the number of colors among the six, and can determine the strength of ocular dominance based on the proportion of the number of colors for the dominant eye.

[0072] The dominant eye determination unit determines which of the left and right test eyes EL and ER is the dominant eye based on the line of sight information of the left and right test eyes EL and ER obtained by objective measurement and the refractive power information of each of the left and right test eyes EL and ER. For example, the dominant eye determination unit determines the eye that is more likely to focus its gaze in the direction of the visual target as the dominant eye based on the line of sight information of the left and right test eyes EL and ER, and determines which of the left and right test eyes EL and ER is trying to focus. Based on the line of sight information of the left and right test eyes EL and ER, the dominant eye determination unit determines the eye that is trying to focus on the visual target as the dominant eye, and determines which of the left and right test eyes EL and ER is trying to focus.

[0073] When the dominant eye test is completed, the determination result output instruction unit outputs an instruction to store the dominant eye determination result, which of the left and right test eyes EL, ER is the dominant eye, in the memory unit 142. The determination results stored in the memory unit 142 can be read by connecting a personal computer (not shown) or the like, and the determination result information, which combines the determination results each time the dominant eye test is performed and the final determination result at the end of the dominant eye test, can be displayed on a screen or printed out by a printer.

[0074] [Dominant Eye Determination Process (FIG. 5)] The dominant eye determination process will be described with reference to the flowchart in FIG. 5, which shows an example of the dominant eye determination process operation. The flowchart in FIG. 5 shows the dominant eye determination process operation when the subjective test & objective measurement mode is selected as the dominant eye test mode. The flowchart in FIG. 5 is started when alignment, which adjusts the positional relationship between the left and right test eyes EL, ER and the left eye measurement head unit 123L and the right eye measurement head unit 123R, has been completed and the dominant eye test setup is complete.

[0075] In step S1, the test distance is set according to the test distance change conditions that affect the determination result when determining the dominant eye from the left and right test eyes EL and ER. In step S1, the test distance is switched and set according to the test distance change conditions (test condition switching step).

[0076] In step S2, following step S1, the corrective optical system is switched and set according to the correction state change conditions that affect the determination result when determining the dominant eye from the left and right test eyes EL and ER (examination condition switching step). This setting of the corrective optical system is optional, and may or may not be corrected. This is because there is a demand to determine the dominant eye while wearing the contact lens prescribed for the test eye. Note that the order of steps S1 and S2 may be reversed.

[0077] Furthermore, the correction values ​​for setting the correction optical system may be determined using the results of the refractive measurement, or the position of the focusing lens 45 may be changed using an RG test until the perfect correction state of the left and right test eyes EL and ER can be confirmed. To prescribe perfect correction values ​​for the left and right test eyes EL and ER, for example, perfect correction values ​​measured by a procedure other than the RG test method may be used, or the current eyeglass prescription values ​​already prescribed for the test eye E may be used, or perfect correction values ​​may be determined by performing multiple subjective tests.

[0078] In step S3, following step S2, a pair of color dot test targets 80 and 81 having different six-color arrangements are projected and presented to the left eye EL and the right eye ER using pattern A or pattern B (target presentation step).

[0079] In step S4, following step S3, a dominant eye test is conducted using binocular vision while presenting a pair of color dot test targets 80 and 81 (a dominant eye test implementation step). In step S4, a subjective test is conducted in which the subject answers questions about the targets they see. In step S4, it is determined which of the left and right test eyes EL and ER is the dominant eye based on the information answered in the subjective test.

[0080] In step S5, following step S3, a dominant eye test is conducted using binocular vision while presenting a pair of color dot test targets 80, 81 (a step for conducting a dominant eye test). In step S5, an objective measurement is conducted that does not require a response from the subject. In step S5, it is determined which of the left and right test eyes EL, ER is the dominant eye based on the results of objective measurements such as gaze detection. Here, the subjective test in step S4 and the objective measurement in step S5 are conducted in parallel. Note that only one of the subjective test and the objective measurement may be conducted.

[0081] In step S6, following step S4 or step S5, it is determined whether or not the change of the plurality of optotype presentation patterns by combination has been completed. If it is determined in step S6 that the change of the optotype presentation patterns has not been completed, the process proceeds to step S7. On the other hand, if it is determined in step S6 that the change of the optotype presentation patterns has been completed, the process proceeds to step S8.

[0082] In step S7, following the determination of NO in step S6, the optotype presentation pattern is changed by at least one of changing the content of the optotype, changing the test distance, and changing the state of the corrective optical system, and the process returns to step S1. Here, the optotype presentation pattern is changed according to a predetermined combination pattern. Also, while the determination of NO in step S6 is made, the processes in steps S1, S2, S3, S4, and S5 are repeated every time the optotype presentation pattern is changed in step S7.

[0083] In step S8, following the determination of YES in step S6, a final determination of the dominant eye from the left and right eyes EL and ER is made, and the process proceeds to END.

[0084] Here, if the final determination of the dominant eye is not automatic but examiner-determined, the examiner may determine which of the left and right test eyes EL, ER is the dominant eye using only the result of the subjective test in step S4. Also, if the final determination of the dominant eye is not automatic but examiner-determined, the examiner may determine which of the left and right test eyes EL, ER is the dominant eye by comprehensively considering the result of the subjective test in step S4 and the result of the objective measurement in step S5.

[0085] When the final determination of the dominant eye is made automatically without the examiner's intervention, the proportion of the left eye that is the dominant eye and the proportion of the right eye that is the dominant eye may be calculated based on answers input in the subjective test, and which of the left and right test eyes EL, ER is the dominant eye may be automatically determined. When the final determination of the dominant eye is made automatically without the examiner's intervention, the determination of the dominant eye may be automatically made based on objective measurement information. Furthermore, when the automatic determination is made using objective measurement information, not only the determination of the dominant eye but also the entire process from the start of measurement to the determination of the dominant eye may be automated.

[0086] [Dominant Eye Determination Action with Optotype Presentation Pattern No. 1 (FIG. 7)] The dominant eye determination action will be described with reference to FIG. 7, which shows an example of subjective test results obtained by implementing a color dot test with optotype presentation pattern No. 1.

[0087] The color dot test of optotype presentation pattern No. 1 is a combination pattern of pattern A + distance vision, pattern B + near vision, pattern B + distance vision, and pattern A + near vision, as shown in Fig. 7. The results of the color dot test of optotype presentation pattern No. 1 shown in Fig. 7 are obtained by repeatedly processing the four combination patterns in the flowchart of Fig. 5.

[0088] In the first embodiment, the pair of optotypes projected onto the left and right test eyes EL and ER are a pair of color dot test optotypes 80 and 81, each with a different color dot arrangement. Therefore, when the left and right test eyes EL and ER are viewed through single-view fusion, the dominant eye can be determined to be the left eye EL or the right eye ER, to which the optotype corresponding to the color perceived through fusion is presented. Therefore, as shown in FIG. 7, the relationship between answers and ocular dominance in Pattern A is: 1: left dominance if red, 2: left dominance if blue, 3: left dominance if green, 4: left dominance if red, 5: left dominance if green, and 6: left dominance if blue. The relationship between answers and ocular dominance in Pattern B is: 1: left dominance if blue, 2: left dominance if green, 3: left dominance if red, 4: left dominance if green, 5: left dominance if blue, and 6: left dominance if red.

[0089] The experimental results for distance vision using pattern A were 83.33% for right-dominant cells and 16.67% for left-dominant cells, as shown in Figure 7. In contrast, the experimental results for near vision using the same pattern A were 66.67% for right-dominant cells and 33.33% for left-dominant cells, as shown in Figure 7. In other words, with pattern A, the right eye dominance weakened when shifting from distance vision to near vision.

[0090] The experimental results for distance vision using pattern B were 83.33% for right-dominant cells and 16.67% for left-dominant cells, as shown in Figure 7. In contrast, the experimental results for near vision using the same pattern B were 33.33% for right-dominant cells and 66.67% for left-dominant cells, as shown in Figure 7. In other words, with pattern B, the dominant eye shifted from the right eye to the left eye when shifting from distance vision to near vision.

[0091] Incidentally, in the total of two tests for distance and near vision, the experimental results for the distance vision condition were as shown in Figure 7, with the number of right-dominant cells being 83.33% and the number of left-dominant cells being 16.67%. In other words, the right eye was determined to be the dominant eye, with strong ocular dominance. In contrast, the experimental results for the near vision condition were as shown in Figure 7, with the number of right-dominant cells being 50.00% and the number of left-dominant cells being 50.00%. In other words, there was no dominant eye, and the result of the test was "no ocular dominance."

[0092] Here, a pair of color dot test optotypes 80, 81 each have a plurality of color dots. Therefore, the dominant eye can be determined based on the percentage [%] of dots perceived as left dominant (number of left dominant cells) and the percentage [%] of dots perceived as right dominant (number of right dominant cells), and the strength of ocular dominance can also be determined. The higher of the left and right eye percentages [%] can be determined to be the dominant eye. A dominant eye percentage [%] of 50%:50% can be determined to be "no ocular dominance." For example, a dominant eye percentage [%] of 70% or more can be determined to be "strong ocular dominance." For example, a dominant eye percentage [%] of 50% to 69% can be determined to be "weak ocular dominance."

[0093] Furthermore, the pair of color dot test optotypes 80, 81 are presented to the left and right test eyes EL, ER in optotype content-changing patterns, i.e., pattern A and pattern B. This prevents bias in the dominant eye determination due to individual differences in the subject's perception of the optotype. For example, if only one pattern is used to project the optotype onto the left and right eyes, bias in the dominant eye determination may occur due to individual differences between the left and right test eyes EL, ER. In contrast, if two patterns, pattern A and pattern B, are used to project the optotype onto the left and right eyes, as shown in FIG. 7 , the number of left dominant cells and the number of right dominant cells differ between pattern A and pattern B, and the positions at which left dominance is indicated and the positions at which right dominance is indicated differ. Therefore, by presenting the pair of color dot test optotypes 80, 81 to the left and right test eyes EL, ER in pattern A and pattern B, the dominant eye determination unit 147 prevents bias in the dominant eye determination and obtains accurate dominant eye determination information.

[0094] Furthermore, a pair of color dot test targets 80, 81 are presented to the left and right test eyes EL, ER under test distance change conditions of distance and near distance. Therefore, the dominant eye determination can grasp the influence of the test distance from the left and right test eyes EL, ER to the target on the dominant eye determination result. As a result, the dominant eye determination can grasp the influence of the test distance on the dominant eye determination result in a pre-test when prescribing a monovision prescription related to distance and near vision, allowing for the appropriate correction power to be set in the monovision prescription. For example, if the ocular dominance at distance is strong, setting the difference in correction power to more than 1D is likely to not cause discomfort to the test subject. However, if the ocular dominance at distance or near distance is weak, or if ocular dominance is reversed between distance and near distance, the difference in correction power must be reduced to approximately 0.5D, or the test subject is likely to feel uncomfortable.

[0095] [Effects of the Ophthalmic Examination Apparatus and Ophthalmic Examination Method] (1) The ophthalmic examination apparatus 100 performs an examination by projecting a visual target onto each of the left and right test eyes EL and ER. The ophthalmic examination apparatus 100 includes a visual target projection system 4 and a control unit 140. The visual target projection system 4 projects at least a pair of visual targets that are partially different in shape or that are recognized as partially different in shape. When performing a dominant eye test using binocular vision, the control unit 140 switches the test conditions according to factors that affect the results of the dominant eye determination, and controls various optical systems and the presentation of visual targets according to the test conditions. When determining which of the left and right eyes is the dominant eye, this ophthalmic examination apparatus 100 can acquire the complex information required for a pre-test for a corrective prescription.

[0096] (2) The control unit 140 presents a pair of optotypes to be projected onto the left and right eyes to be examined using an optotype content change pattern that changes the optotype content, and performs a dominant eye test using binocular vision using multiple optotype presentation patterns that combine the optotype content change pattern and the test conditions. This ophthalmic examination device 100 prevents biased determination of the dominant eye and can obtain accurate information on the dominant eye.

[0097] (3) The control unit 140 performs at least one of a subjective test and an objective measurement each time a dominant eye test is performed, and determines which of the left and right test eyes EL and ER is the dominant eye based on the results. This ophthalmic examination device 100 can determine the dominant eye not only based on the results of a subjective test, but also based on the results of objective measurement, and can also determine the dominant eye based on the results of both a subjective test and objective measurement.

[0098] (4) The influencing factor is the test distance from the positions of the left and right test eyes EL and ER to the position of the optotype, and the test conditions are test distance change conditions that change the test distance, including the distance for far vision and the distance for near vision. The control unit 140 performs a binocular dominant eye test using an optotype presentation pattern for each test distance according to the test distance change conditions. When determining which of the left and right eyes is the dominant eye, this ophthalmic examination device 100 can obtain a determination result in which the influence of whether the test distance is long or short is reflected in the determination of the dominant eye and the strength of ocular dominance.

[0099] (5) The influencing factor is the refractive power of the left and right test eyes EL, ER, and the test condition is a correction state change condition that changes between a non-corrected state and a corrected state. The control unit 140 performs a binocular dominant eye test using a presentation pattern for each correction state according to the correction state change condition. When determining which of the left and right eyes is the dominant eye, this ophthalmic examination device 100 can obtain a determination result in which the influence of whether the left and right test eyes EL, ER are in a corrected state is reflected in the determination of the dominant eye and the degree of ocular dominance.

[0100] (6) The subjective test is a test in which the subject answers questions about the content of optotypes seen in the left and right test eyes EL and ER. When determining the dominant eye based on the answer input in the subjective test, the control unit 140 calculates the percentage of the left eye being the dominant eye and the percentage of the right eye being the dominant eye, and automatically determines which of the left and right test eyes EL and ER is the dominant eye. This ophthalmic examination device 100 can automatically determine the dominant eye and quantitatively determine ocular dominance based on the answer input in the subjective test.

[0101] (7) Objective measurement is a measurement that obtains objective measurement information without requiring responses from the subject. When determining the dominant eye based on the output result of the objective measurement, the control unit 140 automatically determines which of the left and right test eyes EL, ER is the dominant eye based on the objective measurement information. This ophthalmic examination device 100 can automatically determine the dominant eye and quantitatively determine ocular dominance based on the objective measurement information obtained by the objective measurement without requiring input operations.

[0102] (8) When determining the dominant eye, the control unit 140 uses gaze information of the left and right test eyes EL, ER obtained by objective measurement. This ophthalmic examination device 100 can confirm binocular vision and can determine that the fixating eye of the left and right test eyes EL, ER that is fixating on a visual target is the dominant eye. Note that the fixating eye that is fixating on a visual target is likely to be the dominant eye. Examples of the fixating eye include the eye that is fixating closer to the visual target, or the eye that shows less gaze fluctuation when the gaze is measured over time.

[0103] (9) When determining the dominant eye, the control unit 140 uses the refractive power information of each of the left and right test eyes EL and ER obtained by objective measurement. This ophthalmic examination device 100 can determine that the eye that is objectively trying to focus on the visual target is the dominant eye, out of the left and right test eyes EL and ER. Note that the eye that is trying to focus is likely to be the dominant eye. Examples of the eye that is trying to focus include the eye whose refractive power is close to the distance of the visual target when observing the visual target, or the eye whose refractive power shows little fluctuation when measured over time.

[0104] (10) The optotype projection system 4 prepares a pair of color dot test optotypes 80, 81, each consisting of an equal number of color dots arranged in a corresponding relationship such that two dots at corresponding positions are different colors. The control unit 140 performs a subjective test in which the subject answers what colors they saw when viewing the pair of color dot test optotypes 80, 81 through single-view fusion with the left and right test eyes EL, ER. This ophthalmic examination device 100 can accurately determine the dominant eye and the strength of ocular dominance based on the color response results from single-view fusion with the left and right test eyes EL, ER through a color dot test using the pair of color dot test optotypes 80, 81.

[0105] (11) An ophthalmic examination method projects optotypes onto each of the left and right test eyes EL and ER to perform the examination. The ophthalmic examination method includes an examination condition switching step (S1, S2), an optotype presenting step (S3), and a dominant eye test implementation step (S4, S5). The examination condition switching step (S1, S2) switches the examination conditions corresponding to factors that affect the determination result when determining the dominant eye from the left and right test eyes EL and ER. The optotype presenting step (S3) projects and presents a pair of optotypes that are partially different in shape or are recognized as partially different in shape to each of the left and right eyes. The dominant eye test implementation step (S4, S5) presents the pair of optotypes in an optotype presentation pattern according to the examination conditions to perform a dominant eye test using binocular vision. This ophthalmic examination method ( FIG. 5 ) can acquire complex information required for a pre-examination of a corrective prescription when determining which of the left and right eyes is the dominant eye. Embodiment 2

[0106] In the second embodiment, a glare test target is used as the target for the dominant eye test. The second embodiment has the same configuration as that of the first embodiment shown in FIGS. 1, 2, and 3 in terms of the overall configuration of the device, the configuration of the optical system, and the configuration of the control unit, and therefore will not be illustrated or described again.

[0107] [Dominant Eye Test Using a Pair of Glare Test Optotypes (FIGS. 8A, 8B, and 8C)] The optotypes for the dominant eye test used in embodiment 2 are glare test optotypes 82-87 provided on the display 41 of the optotype projection system 4. The glare test optotypes 82-87 are pairs of optotypes in which an image with glare and an image without glare are arbitrarily arranged, and the positional relationship between the image with glare and the image without glare is reversed for the left eye EL and the right eye ER. In embodiment 2, the optotypes are pairs in which an image with glare and an image without glare are arranged vertically, and the vertical positional relationship between the two types of images is reversed for the left eye EL and the right eye ER. Note that the images with glare and the images without glare may be arranged horizontally or diagonally, in addition to being arranged vertically. The glare test optotypes 82-87 are provided in three pairs for different everyday life scenes: a night driving scene, a daytime driving scene, and an alphabet reading scene. Here, the scene of reading the alphabet represents one of the everyday life scenes of reading characters displayed on the screen of a personal computer, a smartphone, etc. Note that as the glare test optotypes, as long as multiple optotype pairs are prepared for different everyday life scenes, for example, four or more pairs of optotype pairs may be prepared.

[0108] Pattern A of the first optotype pair consisting of glare test optotypes 82 and 83 is shown in Figure 8A. The glare test optotype 82 for the left eye EL is an optotype arranged in a vertical row with a road image at night with glare on the upper side and a road image at night without glare on the lower side. The glare test optotype 83 for the right eye ER is an optotype arranged in a vertical row with a road image at night without glare on the upper side and a road image at night with glare on the lower side. Note that although not shown, pattern B of the first optotype pair refers to a left-right reverse pattern in which the glare test optotype 82 for the left eye EL is an optotype for the right eye ER, and the glare test optotype 83 for the right eye ER is an optotype for the left eye EL.

[0109] Pattern A of the second optotype pair consisting of glare test optotypes 84, 85 is shown in Figure 8B. The glare test optotype 84 for the left eye EL is an optotype arranged in a vertical row with a daytime road image without glare on the upper side and a daytime road image with glare on the lower side. The glare test optotype 85 for the right eye ER is an optotype arranged in a vertical row with a daytime road image with glare on the upper side and a daytime road image without glare on the lower side. Note that although not shown, pattern B of the second optotype pair refers to a left-right reverse pattern in which the glare test optotype 84 for the left eye EL is an optotype for the right eye ER, and the glare test optotype 85 for the right eye ER is an optotype for the left eye EL.

[0110] Pattern A of the third optotype pair consisting of glare test optotypes 86 and 87 is shown in Figure 8C. The glare test optotype 86 for the left eye EL is an optotype arranged in a vertical row with the no-glare alphabet on the top and the glare alphabet on the bottom. The glare test optotype 87 for the right eye ER is an optotype arranged in a vertical row with the glare alphabet on the top and the no-glare alphabet on the bottom. Note that although not shown, pattern B of the third optotype pair refers to a left-right reverse pattern in which the glare test optotype 86 for the left eye EL is the optotype for the right eye ER, and the glare test optotype 87 for the right eye ER is the optotype for the left eye EL.

[0111] Here, the different everyday life scenes are not limited to a night driving scene ( FIG. 8A ), a daytime driving scene ( FIG. 8B ), or alphabets ( FIG. 8C ), and may be selected arbitrarily. For example, the everyday life scenes may be determined by preparing as many types of everyday life images as possible and selecting from among them images that represent scenes that each subject frequently encounters in their daily lives.

[0112] The configuration of the control unit 140 related to the dominant eye test in embodiment 2 will be explained in detail by dividing it into an optotype presentation instruction unit, a test condition switching instruction unit, a test information acquisition unit, a dominant eye determination unit, and a determination result output instruction unit.

[0113] The target presentation instruction unit outputs a control instruction to the display 41 of the target projection system 4 to change the target pair for each different daily life scene (nighttime road image → daytime road image → alphabet) when projecting the glare test targets 82 to 87 onto the left and right eyes EL and ER. The target presentation instruction unit defines a left-right normal pattern of the first, second, and third target pairs of the glare test targets 82 to 87 as pattern A. The target presentation unit defines a left-right reverse pattern of the first, second, and third target pairs of the glare test targets 82 to 87 as pattern B. The target presentation instruction unit then outputs a control instruction to the display 41 of the target projection system 4 to present the targets in a target content change pattern that changes between pattern A and pattern B.

[0114] The test condition switching instruction unit basically uses the test distance from the positions of the left and right test eyes EL and ER to the target position and the refractive power of the left and right test eyes EL and ER as influential factors, as in the first embodiment. The test condition switching instruction unit outputs a control instruction to switch the test conditions to the drive motor of the focusing lens 45 of the target projection system 4 and the drive motor of the VCC 48. Note that in the second embodiment, the glare test targets 82 to 87 are used, and therefore the glare specifications (position, size, and light intensity) may be used as influential factors, and the glare position, glare size, and glare light intensity may be changed. When the glare specifications are changed, the adaptive correction optical system can also be evaluated.

[0115] As in the first embodiment, the test information acquisition unit acquires test information necessary for determining the dominant eye by combining a subjective test and an objective measurement. The subjective test is a test in which the subject answers whether "the upper part is too bright," "the lower part is too bright," or "the level of glare is the same" when looking at glare test targets 82 to 87 with both eyes. The test information necessary for determining the dominant eye in the subjective test is response information obtained by manually inputting the subject's response, such as "the lower part is too bright," "the upper part is too bright," etc.

[0116] The dominant eye determination unit determines which of the left and right test eyes EL and ER is the dominant eye based on the response information obtained through the subjective test. For example, when the glare test targets 82 to 87 are presented using pattern A, if the subject answers, for example, "down, up, up," the dominant eye determination unit determines that the right eye ER is the dominant eye and the left eye EL is the non-dominant eye. In other words, the dominant eye determination unit determines that the left eye EL or the right eye ER that answers "dazzling" is the dominant eye. Furthermore, if the dominant eye ratio calculated based on the responses is, for example, 70% or more, the dominant eye determination unit can determine that the right eye ER has strong ocular dominance. Furthermore, if the dominant eye ratio calculated based on the responses is, for example, 50% to 69%, the dominant eye determination unit can determine that the right eye ER has weak ocular dominance. The dominant eye determination unit can determine that there is no ocular dominance if the ratio of the dominant eye calculated based on the answers is 50%:50%.

[0117] When the dominant eye test is completed, the determination result output instruction unit outputs an instruction to store the dominant eye determination result, which of the left and right test eyes EL, ER is the dominant eye, in the memory unit 142. The determination results stored in the memory unit 142 can be read by connecting a personal computer (not shown) or the like, and it is possible to both display on a screen and print out the determination result information, which includes, for example, the determination result each time the dominant eye test is performed and the final determination result at the end of the dominant eye test.

[0118] [Dominant Eye Determination Process (Fig. 9)] The dominant eye determination process will be described with reference to the flowchart of Fig. 9, which shows an example of the dominant eye determination process operation. Note that steps S21, S22, S26, and S28 are steps that perform the same processes as steps S1, S2, S6, and S8 in Fig. 5, and therefore descriptions thereof will be omitted.

[0119] Step S23, following step S22, starts presenting optotypes to the left and right test eyes EL and ER, first presenting a first optotype pair consisting of glare test optotypes 82 and 83 of a nighttime road image. Step S23 then presents a second optotype pair consisting of glare test optotypes 84 and 85 of a daytime road image, and then presents a third optotype pair consisting of glare test optotypes 86 and 87 of alphabet images. When a pattern change command is received in step S27, step S23 presents an optotype content change pattern that changes between pattern A of the glare test optotypes 82 to 87 and pattern B of the glare test optotypes 82 to 87 (optotype presenting step).

[0120] In step S24, following step S23, a dominant eye test is conducted using binocular vision while presenting the glare test targets 82 to 87 (a dominant eye test implementation step). In step S24, a subjective test is conducted in which the subject answers which target is seen (e.g., whether the target is more dazzling, the upper or the lower target, etc.) each time a pair of targets is presented. In step S24, it is determined which of the left and right test eyes EL and ER is the dominant eye based on the information answered in the subjective test.

[0121] In step S25, following step S23, a dominant eye test is conducted using binocular vision while presenting the glare test targets 82 to 87 (a step for conducting a dominant eye test). In step S25, an objective measurement is conducted that does not require a response from the subject. In step S25, it is determined which of the left and right test eyes EL, ER is the dominant eye based on the results of objective measurements such as gaze detection. Here, the subjective test in step S24 and the objective measurement in step S25 are conducted in parallel. Note that only one of the subjective test and the objective measurement may be conducted.

[0122] In step S27, following the determination of NO in step S26, the optotype presentation pattern is changed by changing at least one of the content of the optotype, the test distance, the state of the corrective optical system, and the specifications of the glare. After the optotype presentation pattern is changed in step S27, the process returns to step S21 (optotype presentation pattern change step). Here, the optotype presentation pattern is changed according to a predetermined combination pattern. Also, while the determination of NO in step S26 is made, the processes of steps S21, S22, S23, S24, and S25 are repeated every time the optotype presentation pattern is changed in step S27.

[0123] [Dominant Eye Determination Action with Optotype Presentation Pattern No. 1 (FIG. 10)] The dominant eye determination action will be described with reference to FIG. 10, which shows an example of subjective test results obtained by conducting a glare test with optotype presentation pattern No. 1.

[0124] The glare test for optotype presentation pattern No. 1 is a combination of pattern A + distance vision, pattern B + near vision, pattern B + distance vision, and pattern A + near vision, as shown in Fig. 10. The results of the glare test for optotype presentation pattern No. 1 shown in Fig. 10 are obtained by repeatedly processing the four combination patterns in the flowchart of Fig. 9.

[0125] In the second embodiment, the pairs of optotypes projected onto the left and right test eyes EL and ER in pattern A are the first optotype pair shown in FIG. 8A, the second optotype pair shown in FIG. 8B, and the third optotype pair shown in FIG. 8C. Pattern B is a left-right reverse pattern of pattern A. Therefore, when the left and right test eyes EL and ER look at the pair of optotypes 82 to 87 of glare test optotypes, it can be determined that the left eye EL or the right eye ER, whichever optotype is presented with the more dazzling glare, is the dominant eye. Therefore, the relationship between the answers and ocular dominance in pattern A is as shown in FIG. 10: night road image: if the top is dazzling, left dominance; daytime road image: if the bottom is dazzling, left dominance; and alphabet: if the bottom is dazzling, left dominance. The relationship between answers in pattern B and ocular dominance is as follows: night road image: if the bottom is dazzling, left dominance; daytime road image: if the top is dazzling, left dominance; alphabet: if the top is dazzling, left dominance.

[0126] The experimental results for distance vision using pattern A were 33.33% for right-dominant cells and 66.67% for left-dominant cells, as shown in Figure 10. In contrast, the experimental results for near vision using the same pattern A were 50.00% for right-dominant cells and 50.00% for left-dominant cells, as shown in Figure 10. In other words, the results showed that pattern A was left-dominant for distance vision, and that when shifting from distance vision to near vision, the left ocular dominance weakened, and that there was no ocular dominance for near vision.

[0127] The experimental results for distance vision using pattern B were 100.00% right-dominant cells and 0.00% left-dominant cells, as shown in Figure 10. In contrast, the experimental results for near vision using the same pattern B were 66.67% right-dominant cells and 33.33% left-dominant cells, as shown in Figure 10. In other words, pattern B showed a strong right-dominant effect during distance vision, and the right-dominant effect weakened when shifting from distance vision to near vision.

[0128] Incidentally, in the total of two experiments for distance and near vision, the experimental results for the distance vision condition were as shown in Figure 10, with the number of right-dominant cells being 66.67% and the number of left-dominant cells being 33.33%. In other words, the right eye ER was determined to be the dominant eye and its ocular dominance was weak. The experimental results for the near vision condition were as shown in Figure 10, with the number of right-dominant cells being 58.33% and the number of left-dominant cells being 41.67%. In other words, similar to the experimental results for the distance vision condition, the experimental results were obtained, with the right eye ER being determined to be the dominant eye and its ocular dominance was weak.

[0129] Here, the glare test optotypes 82 to 87 have multiple optotype pairs (the first optotype pair shown in FIG. 8A, the second optotype pair shown in FIG. 8B, and the third optotype pair shown in FIG. 8C). Therefore, the dominant eye can be determined based on the percentage [%] of the number of left-dominant cells and the percentage [%] of the number of right-dominant cells, as in the first embodiment, and the strength of ocular dominance can also be determined.

[0130] The first pair of optotypes, the second pair of optotypes, and the third pair of optotypes made up of the glare test optotypes 82 to 87 are presented to the left and right eyes EL and ER to be examined in optotype content changing patterns of Pattern A and Pattern B. Therefore, as in the first embodiment, the dominant eye determination can prevent biased determination of the dominant eye due to individual differences in the subject's perception of the optotypes, and accurate dominant eye determination information can be obtained.

[0131] Furthermore, the first pair of optotypes, the second pair of optotypes, and the third pair of optotypes made up of the glare test optotypes 82 to 87 are presented to the left and right test eyes EL, ER under test distance change conditions of far vision distance and near vision distance. Therefore, similar to the first embodiment, the dominant eye determination can grasp the influence of the test distance from the left and right test eyes EL, ER to the optotypes on the dominant eye determination result.

[0132] [Effects of Ophthalmic Examination Apparatus and Ophthalmic Examination Method] The ophthalmic examination apparatus 100 and ophthalmic examination method of the second embodiment have the following effects in addition to the effects (1) to (9) and (11) of the first embodiment.

[0133] (12) The target projection system 4 uses a pair of targets, each consisting of an image with glare and an image without glare, arranged arbitrarily, with the positional relationship between the image with glare and the image without glare reversed for the left eye EL and the right eye ER. The target projection system 4 prepares multiple pairs of targets for different everyday life scenes, creating glare test targets 82-87. The control unit 140 performs a subjective test in which the subject answers whether the glare of the image with glare presented to the left eye EL or the glare of the image with glare presented to the right eye ER is more dazzling when viewing the glare test targets 82-87 with both eyes. The ophthalmic examination device 100 performs a glare test using the glare test targets 82-87, and can accurately determine the dominant eye and the strength of ocular dominance based on the answer as to which of the glare images projected onto the left eye EL and the right eye ER is more dazzling. Embodiment 3

[0134] In the third embodiment, a pair of optotypes for a binocular rivalry test is used as the optotype for the dominant eye test. Note that the third embodiment has the same configurations as those shown in Figures 1, 2, and 3 of the first embodiment in terms of the "overall configuration of the device," the "configuration of the optical system," and the "configuration of the control unit," and therefore, illustrations and descriptions thereof will be omitted.

[0135] [Dominant Eye Test Using a Pair of Binocular Rivalry Test Targets (FIGS. 11A and 11B)] The dominant eye test targets used in the third embodiment are a pair of binocular rivalry test targets 88 and 89 provided on the display 41 of the target projection system 4. The pair of binocular rivalry test targets 88 and 89 are made up of two images that cause the phenomenon of binocular rivalry, and have pattern A with a normal left-right pattern and pattern B with an inverted left-right pattern.

[0136] The binocular rivalry test target 88 presented to the left eye EL in pattern A is a black and white striped pattern image tilted 45 degrees upward to the right inside a target frame 88a, as shown in Fig. 11A. The binocular rivalry test target 89 presented to the right eye ER in pattern A is a black and white striped pattern image tilted 45 degrees downward to the right inside a target frame 89a, as shown in Fig. 11A.

[0137] The binocular rivalry test target 89 presented to the left eye EL in pattern B is a black and white striped pattern image tilted 45 degrees downward to the right inside a target frame 89a, as shown in Fig. 11B. The binocular rivalry test target 88 presented to the right eye ER in pattern B is a black and white striped pattern image tilted 45 degrees upward to the right inside a target frame 88a, as shown in Fig. 11B.

[0138] Here, binocular rivalry refers to a phenomenon in which, when the difference between the images seen by both eyes is large, the brain is unable to integrate them into a single image, and only the image seen by one eye is perceived, but which image is perceived cannot be consciously controlled and is switched at irregular intervals. Therefore, the two images used as a pair of binocular rivalry test targets are not limited to inclined striped images such as the binocular rivalry test targets 88 and 89, as long as they are a pair of test targets consisting of two images that cause the phenomenon of binocular rivalry.

[0139] The configuration of the control unit 140 related to the dominant eye test in embodiment 3 will be explained in detail by dividing it into an optotype presentation instruction unit, a test condition switching instruction unit, a test information acquisition unit, a dominant eye determination unit, and a determination result output instruction unit.

[0140] When presenting a pair of binocular rivalry test targets 88, 89 to the left and right test eyes EL, ER, the target presentation instruction unit outputs control instructions to the display 41 of the target projection system 4 to present them in a target content change pattern that changes between projecting a left-right normal pattern (pattern A) and projecting a left-right reverse pattern (pattern B).

[0141] The test condition switching instruction unit sets the test conditions as test distance change conditions, and outputs control instructions to the drive motor of the focusing lens 45 of the target projection system 4 and the drive motor of the VCC 48 to change the test distance between a far-viewing distance (e.g., about 3 m to 6 m) and a near-viewing distance (e.g., about 25 cm to 40 cm).

[0142] The test information acquisition unit acquires test information necessary for determining the dominant eye through a combination of subjective testing and objective measurement. The subjective testing is a test in which, when a pair of binocular rivalry test targets 88, 89 are viewed with both eyes, the right eye time during which the image on the right eye side is seen, the left eye time during which the image on the left eye side is seen, and the time during which there is no ocular dominance are recorded within a set time (e.g., 30 seconds). The test information necessary for determining the dominant eye in the subjective testing is response information obtained by recording the subject's responses to the "right eye time," "left eye time," and "time during which there is no ocular dominance."

[0143] The dominant eye determination unit determines which of the left and right test eyes EL and ER is the dominant eye based on the response information regarding the right eye time, left eye time, and time without ocular dominance. For example, if the right eye time is longer than the left eye time, the dominant eye determination unit determines that the right eye ER is the dominant eye and the left eye EL is the non-dominant eye. Furthermore, if the right eye time is longer than the left eye time, for example, the time ratio is 70% or more, the dominant eye determination unit can determine that the right eye ER has strong ocular dominance. Furthermore, if the right eye time is longer than the left eye time, for example, the time ratio is 50% to 69%, the dominant eye determination unit can determine that the right eye ER has weak ocular dominance. Furthermore, if the right eye time and the left eye time are the same length and the time ratio is 50%:50%, the dominant eye determination unit can determine that there is no ocular dominance.

[0144] When the dominant eye test is completed, the determination result output instruction unit outputs an instruction to store the dominant eye determination result, which of the left and right test eyes EL, ER is the dominant eye, in the memory unit 142. The determination results stored in the memory unit 142 can be read by connecting a personal computer (not shown) or the like, and it is possible to both display on a screen and print out the determination result information, which includes, for example, the determination result each time the dominant eye test is performed and the final determination result at the end of the dominant eye test.

[0145] [Dominant Eye Determination Process (FIG. 12)] The dominant eye determination process will be described with reference to the flowchart of FIG. 12, which shows an example of the dominant eye determination process operation. Note that steps S31, S32, S36, S37, and S38 are steps that perform the same processes as steps S1, S2, S6, S7, and S8 in FIG. 5, and therefore descriptions thereof will be omitted.

[0146] In step S33, following step S32, a pair of binocular rivalry test targets 88 and 89 are projected and presented to the left eye EL and the right eye ER using pattern A or pattern B (target presenting step).

[0147] Step S34, following step S33, involves a subjective test in which the subject answers which of the optotypes they see when conducting a binocular vision dominant eye test while presenting a pair of binocular rivalry test optotypes 88, 89. Step S34 records the right eye time, left eye time, and time without ocular dominance based on the answer information about the optotype content, and determines which of the left and right test eyes EL, ER is the dominant eye based on the recorded results of the subjective test (dominant eye determination step).

[0148] Step S35, following step S33, involves performing an objective measurement that does not require a response from the subject when conducting a binocular vision dominant eye test while presenting a pair of binocular rivalry test targets 88, 89. Step S35 determines which of the left and right test eyes EL, ER is the dominant eye based on the results of objective measurements such as gaze detection (dominant eye determination step). Here, the subjective test in step S34 and the objective measurement in step S35 are performed in parallel. Note that only one of the subjective test and the objective measurement may be performed.

[0149] [Dominant Eye Determination Action with Optotype Presentation Pattern No. 1 (FIG. 13)] The dominant eye determination action will be described with reference to FIG. 13, which shows an example of the subjective test results obtained by conducting a binocular rivalry test with optotype presentation pattern No. 1.

[0150] The binocular rivalry test using optotype presentation pattern No. 1 is a combination pattern of pattern A + distance vision and pattern B + near vision, as shown in Fig. 13. The results of the binocular rivalry test using optotype presentation pattern No. 1 shown in Fig. 13 are obtained by repeatedly processing the two combination patterns in the flowchart of Fig. 12.

[0151] In the third embodiment, the pair of targets projected onto the left and right test eyes EL and ER are a pair of binocular rivalry test targets 88 and 89 with stripes that have different inclination directions. Therefore, when the left and right test eyes EL and ER look at the pair of binocular rivalry test targets 88 and 89, the dominant eye determination is performed by recording the time during which the right eye sees the image on the right eye ER side, the time during which the left eye sees the image on the left eye EL side, and the time during which there is no ocular dominance within a set time (e.g., 30 seconds). Then, the dominant eye determination unit 147" can determine that of the left and right test eyes EL and ER, the left eye EL or the right eye ER that has been there for a longer time is the dominant eye based on the recorded results of the subjective test. Furthermore, the dominant eye determination can calculate the left / right eye ratio taking into account the time without ocular dominance by performing the following calculation. For example, when the set time is 30 seconds, the dominant eye determination calculates the left eye ratio [%] as (right eye time x 0 + left eye time x 2 + time without ocular dominance x 1) / 60*100, and the right eye ratio [%] as 100% - left eye ratio [%]. In this case, the ratio of the time spent looking with either the left or right eye is actually accurate, so the determination of the strength of ocular dominance becomes more accurate. Furthermore, the dominant eye determination may calculate not only the left / right eye ratio but also the ratio of no ocular dominance.

[0152] As shown in Figure 13, the experimental results for the distance vision condition in Pattern A were: right eye time 14.42 seconds, left eye time 14.26 seconds, and no ocular dominance time 1.32 seconds. When the time without ocular dominance was also taken into consideration, the right eye ratio was 50.27% and the left eye ratio was 49.73%. In other words, in the distance vision condition in Pattern A, the dominant eye was the right eye ER, and the results showed that there was only a slight difference in ocular dominance between the right eye ER and the left eye EL.

[0153] As shown in Figure 13, the experimental results for near vision conditions using Pattern B were: right eye time 5.83 seconds, left eye time 9.84 seconds, and no ocular dominance time 14.33 seconds. When the time without ocular dominance was also taken into account, the right eye ratio was 43.32% and the left eye ratio was 56.68%. In other words, under near vision conditions using Pattern B, the dominant eye was the left eye EL, and the results showed that there was only a slight difference in ocular dominance between the right eye ER and the left eye EL.

[0154] Thus, it became clear that the right eye ER tends to be the dominant eye for far vision, and the left eye EL tends to be the dominant eye for near vision. It was also revealed that the left and right eyes EL and ER have a weak level of ocular dominance, regardless of the presentation of optotypes in Pattern A and Pattern B, or whether they are far vision or near vision.

[0155] In this experimental example, the left eye ratio and right eye ratio were calculated without considering the time when there was no ocular dominance, but the left eye ratio and right eye ratio may also be calculated taking into consideration the time when there was no ocular dominance. In this case, the time ratio of which eye (EL, ER) is looking is actually based on the left and right test eyes, so that the determination of whether ocular dominance is strong or weak can be made accurately.

[0156] [Effects of Ophthalmic Examination Apparatus and Ophthalmic Examination Method] The ophthalmic examination apparatus 100 and ophthalmic examination method of the third embodiment have the following effects in addition to the effects (1) to (9) and (11) of the first embodiment.

[0157] (13) The visual target projection system 4 provides a pair of visual targets 88, 89 for binocular rivalry test, which are images that cause binocular rivalry. The control unit 140 executes a subjective test by viewing the pair of visual targets 88, 89 with both eyes, recording the right eye time during which the image on the right eye ER side is seen, the left eye time during which the image on the left eye EL side is seen, and the time during which no ocular dominance is observed within a set time. The ophthalmic examination device 100 performs a binocular rivalry test using the pair of visual targets 88, 89 for binocular rivalry, and can accurately determine the dominant eye and the strength of ocular dominance based on the recorded results of the right eye time and left eye time.

[0158] The above description is based on the drawings of the ophthalmic examination apparatus 100 and ophthalmic examination method of Embodiments 1 to 3. However, the specific configurations of the ophthalmic examination apparatus and ophthalmic examination method of the present disclosure are not limited to those shown in Embodiments 1 to 3. The ophthalmic examination apparatus and ophthalmic examination method of the present disclosure are permitted to be modified or added to in design as long as they do not deviate from the gist of the invention according to each claim in the scope of the claims.

[0159] The optotype projection system 4 of the first to third embodiments illustrates examples in which a pair of color dot test optotypes 80 and 81, multiple pairs of glare test optotypes 82 to 87, and a pair of binocular rivalry test optotypes 88 and 89 are set as optotypes. However, the optotype projection system is not limited to these examples of optotypes with at least one pair. The at least pair of optotypes is not limited to color dot test optotypes, glare test optotypes, and binocular rivalry test optotypes, as long as they are optotypes with partial differences in shape, such as color or shape. Furthermore, the at least pair of optotypes may not be optotypes with partial differences in shape, such as color or shape, but may be the same optotype that is perceived as partially different in shape when viewed with the left and right eyes by using a filter, polarized lenses, or the like. An optotype perceived as partially different in shape may be, for example, the optotype 90 shown in FIG. 14 viewed without a filter or polarized lenses, and the optotype 90 shown in FIG. 14 viewed through an RG filter. When viewed through an RG filter, the color of the white circle portion of the optotype 90 changes. The optotype 90 shown in Fig. 14 is an optotype used in the Worth four-light test, which is a test method for checking the presence or absence of binocular fixation, suppression, and diplopia. The Worth four-light test involves wearing glasses with red on the right and green on the left, showing four lights - white (bottom), red (top), green (center left), and green (center right) - to the subject, who is asked to answer the number and color of the lights.

[0160] The ophthalmic examination device 100 of the first to third embodiments is an example of an objective measurement device with a subjective test function using an internal target, which is equipped with a target presentation function, a phoropter function, and an autorefractometer / keratomileusis measurement function. However, the ophthalmic examination device is not limited to the device configuration examples of the first to third embodiments. For example, the ophthalmic examination device may be an example that performs only a subjective test using a target projection device that presents a real target and prescribes a state in which the test distance changes. When a real target is presented, a polarizing filter or the like is used to make separate targets visible to both eyes. The ophthalmic examination device may also be an example that is configured as a combined device of a subjective test device and an objective measurement device.

[0161] The ophthalmic examination apparatus 100 of the first to third embodiments has shown an example in which the influencing factor for switching examination conditions is the examination distance, and the examination condition is a test distance change condition that changes the far vision distance and the near vision distance. However, the examination condition switching is not limited to this. The examination condition switching may be an example in which the examination distance is changed in multiple stages, three or more stages, instead of two stages.

[0162] In the ophthalmic examination apparatus 100 of the first and second embodiments, the influencing factor is the refractive power, and the examination condition is a correction state change condition that changes between a non-corrected state and a fully corrected state. However, the examination condition change is not limited to this. For example, the examination condition change may be an example in which the examination is performed using a plurality of monovision reproduction prescriptions with different refractive power correction values ​​for the left and right eyes as the correction state change condition.

[0163] The ophthalmic examination apparatus 100 of the first to third embodiments has shown an example in which a pair of optotypes is projected onto the left and right eyes EL and ER to be examined, and the pair of optotypes is presented in an optotype content change pattern (pattern A and pattern B) that changes the optotype content. However, the optotype presentation may be an example in which the optotype presentation pattern is one type of pattern using a pair of optotypes.

[0164] In the ophthalmic examination apparatus 100 of Embodiments 1 and 2, an example was shown in which the number of measurements when the test distance is a distance distance and the number of measurements when the test distance is a near distance were set to a maximum of two in an experiment. In the ophthalmic examination apparatus 100 of Embodiment 3, an example was shown in which the number of measurements when the test distance is a distance distance and the number of measurements when the test distance is a near distance were set to one each in an experiment. However, the number of measurements at a certain test distance is not limited to a maximum of two or one for each. For example, the number of measurements when the test distance is a distance distance and the number of measurements when the test distance is a near distance may each be set to three or more. When the number of measurements is set to multiple, the dominant eye may be determined from the average value, and a larger number of measurements may result in more accurate measurement results.

[0165] Although the ophthalmic examination device 100 in the first to third embodiments is described as an example of performing only a binocular dominant eye test, it may also be combined with a visual acuity test. That is, when performing a dominant eye test, a visual acuity test may be performed at the position of a dominant eye determination target. In this case, the timing of the visual acuity test may be any timing, such as before or after the dominant eye determination. If the visual acuity test is performed before the dominant eye determination, a prescription may be made to minimize the difference in visual acuity between the two eyes. The results of the visual acuity test allow the examiner to determine whether the eye viewing the target is truly the dominant eye or whether it is simply seeing better than the fellow eye. Furthermore, if the results of the visual acuity test indicate poor visual acuity and the target is not visible, the examiner can recognize that the reliability of the dominant eye determination result is low or that the dominant eye determination result was obtained in a poorly visible state. Furthermore, the reliability of the dominant eye determination (the reliability of the value obtained for ocular dominance) may be calculated and displayed from the visual acuity test results. The reliability index is calculated, for example, according to an increase in the difference in decimal visual acuity values ​​between the left and right eyes or a decrease in the decimal visual acuity values, and serves as an index for determining when there is a problem with vision that may affect the determination of the dominant eye, such as when the difference in decimal visual acuity values ​​between the left and right eyes is greater than 0.5 or when the visual acuity of one eye is 0.8 or less in decimal visual acuity.

[0166] Although the ophthalmic examination device 100 of the first to third embodiments has been described as an example in which only a binocular vision dominant eye test is performed, it may also be an example in which a dominant eye test is combined with wavefront aberration measurement. That is, a wavefront aberration measurement unit may be provided to measure the wavefront aberration of the eye and calculate the eye's refraction from the wavefront aberration. This timing may be any timing, such as before or after the dominant eye determination, as in the case of a visual acuity test. Furthermore, as in the case of a visual acuity test, the appearance of the optotype may be estimated from the amount of wavefront aberration of the eye, and a reliability index may be calculated and displayed. For example, the reliability index may be a value that decreases as the amount of wavefront aberration of the eye increases, or a simulation of the optotype from the wavefront aberration may be performed, and the degree of blur may be quantified by pattern matching with the original optotype, and a value corresponding to that value may be displayed. Furthermore, the examiner may determine the reliability of the dominant eye determination based on the appearance of the simulated image. CROSS-REFERENCE TO RELATED APPLICATIONS

[0167] This application claims priority based on Japanese Patent Application No. 2024-143340, filed with the Japan Patent Office on August 23, 2024, the entire disclosure of which is incorporated herein by reference in its entirety.

Claims

1. An ophthalmic examination device that performs an examination by projecting a visual target onto each of the left and right eyes to be examined, characterized by having: a visual target projection system that projects at least a pair of visual targets that are partially different in shape or that are recognized as being partially different in shape as the visual targets; and a control unit that, when performing a dominant eye test using binocular vision, switches the test conditions according to influencing factors that affect the determination result of the dominant eye, and controls various optical systems and the presentation of the visual targets according to the test conditions.

2. An ophthalmic examination device according to claim 1, wherein the control unit presents the pair of optotypes to be projected onto the left and right eyes to be examined using an optotype content change pattern that changes the optotype content, and the dominant eye test using binocular vision is carried out using a plurality of optotype presentation patterns that combine the optotype content change pattern and the test conditions.

3. An ophthalmic examination device according to claim 1, characterized in that the control unit performs at least one of a subjective test and an objective measurement each time the dominant eye test is performed, and determines which of the left and right test eyes is the dominant eye based on the results.

4. An ophthalmic examination device according to claim 1, wherein the influencing factor is the test distance from the positions of the left and right eyes to the position of the target, the test conditions are test distance change conditions that change the test distance including the distance to see far and the distance to see near, and the control unit performs the binocular dominant eye test using a target presentation pattern for each test distance according to the test distance change conditions.

5. An ophthalmic examination device according to claim 1, wherein the influencing factors are the refractive powers of the left and right eyes to be examined, the examination conditions are correction state change conditions that change between a non-corrected state and a corrected state, and the control unit performs the dominant eye examination using binocular vision using an optotype presentation pattern for each correction state according to the correction state change conditions.

6. An ophthalmic examination device according to claim 3, wherein the subjective test is a test in which the subject answers about the contents of the visual targets seen by the left and right eyes to be examined, and the control unit, when determining the dominant eye based on the answers input in the subjective test, calculates the proportion of the left eye being the dominant eye and the proportion of the right eye being the dominant eye, and automatically determines which of the left and right eyes to be examined is the dominant eye.

7. An ophthalmic examination device according to claim 3, wherein the objective measurement is a measurement that obtains objective measurement information without requiring a response from the subject, and the control unit, when determining the dominant eye based on the output result of the objective measurement, automatically determines which of the left or right eye to be examined is the dominant eye based on the objective measurement information.

8. An ophthalmic examination apparatus according to claim 7, characterized in that the control unit uses the gaze information of the left and right examined eyes obtained by the objective measurement when determining the dominant eye.

9. An ophthalmic examination apparatus according to claim 7, characterized in that the control unit uses the refractive power information of each of the left and right examined eyes obtained by the objective measurement when determining the dominant eye.

10. An ophthalmic examination device according to any one of claims 1 to 9, wherein the optotype projection system provides a pair of color dot test optotypes, each of which is an equal number of color dots arranged in a corresponding relationship such that two dots at corresponding positions are different colors, and the control unit executes a subjective test in which the subject answers what colors they see when they view the pair of color dot test optotypes with the left and right eyes of the subject using single-view fusion.

11. An ophthalmic examination device according to any one of claims 1 to 9, wherein the target projection system is configured to provide a pair of targets in which images with glare and images without glare are arbitrarily arranged, with the positional relationship between the images with glare and the images without glare being reversed for the left eye and the right eye, and a plurality of such target pairs are provided for different everyday life scenes to provide glare test targets, and the control unit is configured to perform a subjective test in which, when the glare test target is viewed with both eyes, the subject is asked to respond as to whether the glare of the image with glare presented to the left eye or the glare of the image with glare presented to the right eye is dazzling.

12. An ophthalmic examination device according to any one of claims 1 to 9, wherein the target projection system provides a pair of binocular rivalry test targets that cause the phenomenon of binocular rivalry as the pair of targets, and the control unit performs a subjective test that records, when the pair of binocular rivalry test targets are viewed with both eyes, the right eye's time during which an image on the right eye side is seen, the left eye's time during which an image on the left eye side is seen, and the time during which there is no ocular dominance, within a set time.

13. An ophthalmic examination device according to claim 1, characterized in that the control unit, when conducting a binocular vision dominant eye test, also conducts a test different from the dominant eye test, and uses parameters obtained using the test different from the dominant eye test to calculate a reliability index, which is the reliability of the dominant eye determination value obtained by the dominant eye test.

14. An ophthalmic examination method for projecting a visual target onto each of the left and right eyes to be examined and conducting an examination, comprising: an examination condition switching step for switching examination conditions corresponding to influencing factors that affect the determination result when determining the dominant eye from the left and right eyes to be examined; an optical target presenting step for projecting and presenting a pair of optical targets that are partially different in shape or are recognized as being partially different in shape to each of the left and right eyes; and a dominant eye examination implementation step for presenting the pair of optical targets in an optical target presentation pattern according to the examination conditions and conducting a dominant eye examination using binocular vision.

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