Optometric device

Abstract

The present invention addresses the problem of providing an optometric device that, when an optical member is set and a pseudo refractive power test is performed, prevents a decrease in test precision caused by changing the apparent size of a visual target presented at a far test distance position. An optometric device (1) comprises a reflector head (100) that has an optometric window (114) for observing a visual target M, a visual target presentation device (200) that presents a visual target M at a far test distance position, and a control unit (330) that controls the parts of the device. The reflector head (100) sets, at the position of the optometric window (114) which is disposed in front of an eye E being examined, a spherical lens that is used to simulatively present, as a near-distance visual target at a near test distance position, a visual target M which is presented at a far test distance position. The control unit (330) has a visual target rendering magnification alteration unit (336) that, when the spherical lens is set and a pseudo near-distance test is performed, changes the rendering magnification β of the visual target M displayed on the visual target presentation device (200) to a magnification that suppresses a change in the apparent size of the visual target M presented at the far test distance position.

Description

Ophthalmic apparatus

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

[0002] As a conventional subjective ophthalmic apparatus, an apparatus having a visual target, a deflecting unit, a calculation unit, and an arranging unit is known. The visual target is presented at a first distance from the eye to be examined. The deflecting unit forms a second optical path for the eye to be examined to visually recognize the visual target as if the visual target is presented at a second distance shorter than the first distance by deflecting a first optical path formed between the eye to be examined and the visual target. The calculation unit calculates an accommodation stimulus amount for the eye to be examined to visually recognize the visual target as if it is presented at the second distance based on the accommodative convergence power generated in the eye to be examined by the second optical path, the first distance, and the second distance. The arranging unit arranges a spherical lens having a spherical power corresponding to the accommodation stimulus amount calculated by the calculation unit in the second optical path (see Patent Document 1).

[0003] Japanese Unexamined Patent Application Publication No. 2014-46022

[0004] When performing a pseudo near vision test in which a visual target presented at a distance inspection distance is used as a pseudo near vision target, the subjective ophthalmic apparatus described in Patent Document 1 arranges an optical member (spherical lens) that applies an accommodation stimulus at a position in front of the eye to be examined.

[0005] However, when performing a pseudo near vision test, the conventional apparatus arranges the spherical lens at a position in front of the eye to be examined that is different from the pupil position of the eye to be examined, so that the apparent size of the visual target presented at the distance inspection distance changes. Therefore, there is a problem that the pseudo near vision test by the conventional apparatus cannot perform a near vision test with the same accuracy (size of the visual target) as a test performed by arranging a real near vision chart at the actual near vision inspection distance.

[0006] The present disclosure has been made paying attention to the above problems, and an object thereof is to provide an ophthalmic apparatus that prevents a decrease in inspection accuracy due to a change in the apparent size of a visual target presented at the position of a first inspection distance when performing a pseudo refractive power inspection by setting an optical member.

[0007] The optometry apparatus of this disclosure comprises an examination unit having an optometry window for observing a target with the eye under examination, a target presentation device for presenting the target at a first examination distance relative to the eye under examination, and a control unit for controlling each part of the apparatus. The examination unit sets an optical member at the position of the optometry window, which is positioned in front of the eye under examination, to simulate the target presented at the first examination distance as a target presented at a second examination distance shorter than the first examination distance. When the control unit sets the optical member and performs a simulated refractive power test, it has a target drawing magnification changing unit that changes the drawing magnification of the target displayed on the target presentation device to a magnification that suppresses changes in the apparent size of the target presented at the first examination distance.

[0008] The optometry device of this disclosure can prevent a decrease in examination accuracy due to a change in the apparent size of the visual target presented at a first examination distance when an optical element is set and a simulated refractive power test is performed.

[0009] This is an external perspective view showing the entire optometry device of Embodiment 1. This is a front view from the target side showing the measuring head provided in the optometry device. This is a rear view from the eye side showing the measuring head provided in the optometry device. This is a cross-sectional view taken along line B-B in Figure 3 showing the internal structure of the measuring head. This is a diagram showing an example of a lens disc built into the measuring head. This is a block diagram showing the control system of the optometry device centered on the controller device of Embodiment 1. This is an explanatory diagram showing the situation of near vision testing using a paper near vision chart. This is a flowchart showing the magnification calculation process in the drawing magnification calculation unit. This is a flowchart showing the processing flow from preparation to start of a simulated near vision test. This is an explanatory diagram showing the change in convergence angle accompanying the transition from distance vision testing to a simulated near vision test. This is a conceptual diagram (a) showing the visual angle when looking at the gap in the Landolt ring 5 m away from the eye under examination, and a conceptual diagram (b) showing the change in visual angle when looking at the gap in the Landolt ring with spectacle lenses in. This is a conceptual diagram showing the change in visual angle when looking at the gap in the Landolt ring with spectacle lenses placed at a distance from the corneal vertex of the eye under examination equal to the intervertex distance. This is a block diagram showing the control system of the ophthalmoscopic device, centered on the controller device of Embodiment 2. This is a diagram showing an example of a drawing magnification table set in the drawing magnification table setting unit.

[0010] The ophthalmic examination apparatus of this disclosure will be described with reference to drawings showing the ophthalmic examination apparatus of Embodiment 1 and the ophthalmic examination apparatus of Embodiment 2 for implementing it. <Embodiment 1>

[0011] [Overall Configuration of the Apparatus (Figure 1)] Figure 1 shows the overall configuration of the optometry apparatus of Embodiment 1. The optometry apparatus 1 comprises a refractor head 100 (optometry unit) through which the subject 2 observes the target M through the optometry window 114, a target presentation device 200 that presents the target M at the distance testing distance, and a controller device 300 operated by the examiner 3.

[0012] The refractor head 100 has an eye examination window 114 for observing a target M with the eye E under examination, and holds a spherical lens or the like set in the position of the eye examination window 114 in a switchable manner. The refractor head 100 includes a side table 101, a vertical support column 102, a horizontal support column 103, a head support 104, and a pair of measuring heads 105, 105. The vertical support column 102 is provided from the side table 101. The horizontal support column 103 is provided on the upper part of the vertical support column 102. The head support 104 is the end of the horizontal support column 103 and is supported above the examination table 4. The pair of measuring heads 105, 105 are provided so as to be rotatable horizontally relative to the head support 104.

[0013] The target presentation device 200 presents a target M to the eye E under examination at a distance testing distance (an example of a first testing distance). The target presentation device 200 includes a device stand 201, a target display main unit 202, and a target display screen 203. The target display main unit 202 is provided at the upper end of the device stand 201. The target display screen 203 is positioned in front of the target display main unit 202, facing the subject 2. The target display screen 203 displays the target M to be presented to the eye E under examination. The target display screen 203 uses panel display devices such as an LCD display (LCD: Liquid Crystal Display) or an organic EL display (EL: Electro Luminescence). The panel display device allows for free modification of the shape and size of the target M displayed on the target display screen 203 via control commands.

[0014] The target M displayed on the target display screen 203 is determined by the examiner 3 using the controller device 300 to select it from a group of target icons on the target chart. When measuring refractive power, the target M (Landolt ring) displayed on the target display screen 203 is changed by displaying different target Ms from the target chart with different visual angles. Note that the target M used for measuring distance visual acuity displayed on the target display screen 203 is not limited to the Landolt ring shown in Figure 1, but may be other distance targets.

[0015] The controller device 300 is placed on the examination table 4 and has a control unit 330 (see Figure 6) that controls each part of the optometry device 1 (refractor head 100, target presentation device 200). As shown in Figure 1, the controller device 300 uses a personal computer having an operating unit 310 and a monitor unit 320. The operating unit 310 is generally composed of, for example, an operating panel 311, a first mouse 312, and a second mouse 313. The monitor unit 320 has a display screen. The first mouse 312 is operated by the examiner 3. The second mouse 313 is operated by the subject 2.

[0016] The input of the first mouse 312 may be replaced by keyboard input. The first mouse 312 and the second mouse 313 of the operating unit 310 may be other devices (operating terminals such as pointing devices, levers, and various controllers). Furthermore, the controller device 300 may be configured to connect the refractor head 100 and the target presentation device 200 via a network. In this case, the examiner 3 can remotely operate the refractor head 100 and the target presentation device 200 using the controller device 300 or a tablet terminal.

[0017] [Detailed Configuration of the Measurement Head (Figures 2-5)] Figure 2 shows the target side of the pair of measurement heads 105, 105. The target side of the measurement head 105 includes a spirit level 106, a head fixing lever 107, a horizontal adjustment knob 108, a fixing screw 109, a rangefinder mounting section 110, a near point illumination 111, a forehead rest knob 112, a corneal aiming window 113, and a target-side eye examination window 114a. Figure 3 shows the subject side of the pair of measurement heads 105, 105. The subject side of the pair of measurement heads 105 includes a subject-side eye examination window 114b, an arm mounting shaft 115, a forehead rest 116, a cheek rest 117, a corneal aiming device 118, and a corneal illumination 119.

[0018] In this case, the near-field inspection, which is performed by setting the near-field chart at the actual near-field inspection distance, uses the near-field meter mounting section 110 and the near-field illumination 111. This near-field inspection is performed by attaching a near-field rod 120, which also serves as a distance meter, to the near-field meter mounting section 110, suspending the near-field chart 121 at the near-field inspection distance of the near-field rod 120 (for example, about 30 cm to 50 cm), and illuminating it with the near-field illumination 111 (see Figure 7).

[0019] The vertex distance VD to the spherical lens set in the ophthalmography window 114 is adjusted using the forehead knob 112, the corneal aiming window 113, and the corneal aiming device 118. To adjust the vertex distance VD, the user looks through the corneal aiming window 113 and rotates the forehead knob 112 while observing the scale on the corneal aiming device 118 to adjust the vertex distance VD from the corneal apex of the eye being examined to the spherical lens to the desired distance (for example, 12 mm).

[0020] Figure 4 shows the internal structure of the measuring head 105. The measuring head 105 has a spherical lens disc unit 130 inside the measuring head housing 122, which has a plurality of spherical lenses arranged in a circular pattern along the outer peripheral region of a disc shape. The spherical lens disc unit 130 is composed of, for example, a first lens disc 131, a second lens disc 132, and a third lens disc 133. When observing the target M, the measuring head housing 122 has a subject-side eye examination window 114b, the first lens disc 131, the second lens disc 132, the third lens disc 133, and a target-side eye examination window 114a arranged in order from the eye E to the target M. The first lens disc 131, the second lens disc 132, and the third lens disc 133 are each rotatably mounted around a lens disc support shaft 123. The first lens disc 131, the second lens disc 132, and the third lens disc 133 can each be independently rotated by a motor (not shown). The first lens disc 131, the second lens disc 132, and the third lens disc 133 are controlled by rotational drive commands output from the control unit 330 to the motors, and the lenses with the determined refractive power are set in the positions of the eye examination window 114.

[0021] Figure 5 shows the first lens disk 131. The first lens disk 131 has an open window 131a, a first lens 131b, a second lens 131c, a third lens 131d, a fourth lens 131e, a fifth lens 131f, a sixth lens 131g, a seventh lens 131h, and an eighth lens 131i on the same circumference. The second lens disk 132 and the third lens disk 133 have the same configuration as the first lens disk 131, except that they are combinations of multiple spherical lenses with different refractive powers. In Figure 5, "-0.25D", "-0.5D", "-0.75D", etc. are written on each spherical lens. A minus sign indicates a concave lens, a plus sign indicates a convex lens, and D represents a diopter (unit of lens refractive power). Furthermore, the diopter D, which is set in the position of the ophthalmography window 114, is configured to be adjustable in intervals of 0.25D depending on the spherical lenses used individually or in combination.

[0022] [Detailed Configuration of the Controller Device (Figures 6 and 7)] Figure 6 shows a block diagram of the control system centered on the controller device 300. The controller device 300 is generally composed of an operation main unit 310, a monitor unit 320, a control unit 330, and a storage unit 340.

[0023] The main operating unit 310 inputs necessary information, such as the near vision test distance, to the control unit 330 when performing distance vision tests or simulated near vision tests on the eye under examination E. The monitor unit 320 displays necessary information, such as the distance corrective refractive power and near vision test distance, when performing distance vision tests or simulated near vision tests on the eye under examination E. Based on the input information from the main operating unit 310, the control unit 330 controls the switching of the spherical lens set in the eye examination window 114 of the refractor head 100, and also controls the drawing magnification of the visual target M displayed on the visual target presentation device 200. The memory unit 340 can exchange information with the control unit 330 and stores the necessary examination information when performing distance vision tests or simulated near vision tests on the eye under examination E.

[0024] The control unit 330 includes a distance correction refractive power setting unit 331, a near-vision inspection distance setting unit 332, an optical element set control unit 333, a convergence angle change control unit 334, a drawing magnification calculation unit 335, and a target drawing magnification change unit 336.

[0025] The distance vision correction power setting unit 331 sets the distance vision correction power of the eye E being examined based on input operations by the examiner 3. For example, if the distance vision test of the eye E being examined is performed prior to the simulated near vision test, the distance vision correction power determined in the distance vision test is set. Alternatively, if the distance vision correction power of the subject 2 is known in advance from past examination data, the distance vision correction power from the examination data may be set.

[0026] The close-range inspection distance setting unit 332 can be set to any close-range inspection distance (an example of a second inspection distance) when performing a simulated close-range inspection. Any close-range inspection distance can be, for example, 1 m, 50 cm, 40 cm, 33.3 cm, etc.

[0027] The optical component set control unit 333 sets a spherical lens (optical component) in the position of the eye examination window 114, which is positioned in front of the eye E, to operate the target M presented at the distance examination distance (5 m) as a near-vision target presented at the near-vision examination distance. In other words, the optical component set control unit 333 uses the spherical lens to add an accommodative stimulus that requires the eye E to focus at the set near-vision examination distance, thereby operating the target M at the distance examination distance as a near-vision target presented at the near-vision examination distance.

[0028] When performing a simulated near vision test on an eye E using an emmetropic eye that does not require distance correction lenses, the optical component set control unit 333 selects a spherical lens to match only the near vision test distance set by the near vision test distance setting unit 332. The optical component set control unit 333 then controls the setting of the selected spherical lens in the eye examination window 114 of the refractor head 100. The refractive power of the spherical lens at this time is -1.00D when the near vision test distance is 1m, -2.00D when the near vision test distance is 50cm, -2.50D when the near vision test distance is 40cm, and -3.00D when the near vision test distance is 33.3cm.

[0029] The optical component set control unit 333, when performing a simulated near vision test on an eye E requiring distance correction lenses, selects a spherical lens that matches the set near vision test distance and distance correction refractive power, and controls the setting of the selected spherical lens at the eye examination window 114 of the refractor head 100. Specifically, the optical component set control unit 333 selects a spherical lens with a diopter sum value Dadd, which is obtained by adding a second diopter D2 (matching the distance correction refractive power) to a first diopter D1 (matching the near vision test distance). The diopter sum value Dadd for the spherical lens set at the eye examination window 114 is set by the rotational drive control of the first lens disc 131, the second lens disc 132, and the third lens disc 133, either individually or in combination.

[0030] The convergence angle change control unit 334 controls the convergence angle when viewing the target M with binocular vision, in accordance with the near vision test distance set by the near vision test distance setting unit 332, when an optical element is set and a simulated near vision test is performed. In other words, the convergence angle change control unit 334 uses the prisms 124, 124 provided on the pair of measuring heads 105, 105 of the refractor head 100 to control the change in the convergence angle by adding a convergence stimulus through the convergence of both eyes (see Figure 10). Here, the convergence angle refers to the inward angle caused by the convergence of the eyeballs when the line of sight changes from the line of sight viewed at the distance test distance to the line of sight viewed at the near vision test distance, when capturing the visual target M with binocular vision, and the line of sight changes.

[0031] The drawing magnification calculation unit 335 uses the distance corrective refractive power D, the intervertex distance VD (the distance from the corneal vertex of the eye E to the spectacle lens), the near vision examination distance ND, and the distance vision examination distance FD to calculate the drawing magnification β of the visual target M displayed on the visual target presentation device 200. The detailed calculation process of the drawing magnification β will be described later.

[0032] The target drawing magnification changing unit 336 controls the drawing magnification β of the target M displayed on the target presentation device 200 to a magnification that suppresses changes in the apparent size of the target M presented at the first test distance when an optical element is set and a simulated refractive power test is performed. In Embodiment 1, when a spherical lens is set and a simulated near vision test is performed, the target drawing magnification changing unit 336 changes the drawing magnification β of the target M displayed on the target presentation device 200 to a magnification that makes it appear the same size as when viewing a near vision chart placed at the actual near vision distance with distance refractive power corrected. That is, when a spherical lens is set at the position of the eye examination window 114 and a simulated near vision test is performed, the target drawing magnification changing unit 336 changes the size of the target M displayed on the target presentation device 200 by the drawing magnification β calculated by the drawing magnification calculation unit 335.

[0033] [Drawing Magnification Calculation Process in the Drawing Magnification Calculation Unit (Figure 8)] Figure 8 shows the drawing magnification calculation process in the drawing magnification calculation unit 335. In this drawing magnification calculation process, the distance corrective refractive power is D, the vertex distance is VD (12 mm), the near examination distance is ND, and the distance examination distance is FD (5 m).

[0034] Step 335a calculates the focal length f of the spectacle lens using the distance correction power D and the formula described within the step frame.

[0035] Step 335b calculates the image position S' of the eye being examined using the focal length f, the vertex distance VD, and the formula described within the step frame. This formula for calculating the image position S' of the eye being examined uses the lens formula (1 / a + 1 / b = 1 / f) to determine where the image of the eye being examined E is formed by the spectacle lens (distance lens).

[0036] Step 335c calculates the near-vision distance L from the image of the eye E using the position of the eye image S', the vertex distance VD, the near-vision distance ND, and the formula described within the step frame. The formula for calculating the near-vision distance L is such that (ND - VD) represents the position of the spectacle lens, and the position of the eye image S' due to the distance corrective refractive power D is further taken into account. The near-vision distance L is equal to the near-vision distance ND when the distance corrective refractive power D is D = 0 (emmetropic eye), is longer than the near-vision distance ND when D > 0 (hyperopia), and is shorter than the near-vision distance ND when D < 0 (myopia).

[0037] Step 335d calculates the near-vision distance ratio h using the near-vision examination distance L of the eye image being examined, the near-vision examination distance ND, and the formula described within the step frame. The near-vision distance ratio h is 1 when the distance corrected refractive power D is D = 0 (emmetropic eye), greater than 1 when D > 0 (hyperopic eye), and less than 1 when D < 0 (myopic eye). In other words, the near-vision distance ratio h represents the ratio to the true value, where the true value is the size when viewing the near-vision chart 121 placed at the actual near-vision distance with the distance refractive power corrected.

[0038] Step 335e calculates the diopter D' needed to reach the near vision test distance ND using the distance corrected refractive power D, the near vision test distance ND, and the formula described within the step frame. When the distance corrected refractive power D is D=0 (emmetropic eye) and the near vision test distance ND is 40cm, the diopter D' is -2.5D. When D>0 (hyperopia) or D<0 (myopia) and the near vision test distance ND is 40cm, the diopter D' is the value obtained by D' = (distance corrected refractive power - 0.25D).

[0039] Step 335f calculates the focal length f' by converting the diopter D' into focal length when an accommodation stimulus is added, using the diopter D' and the formula described in the step frame.

[0040] Step 335g calculates the image position S'' of the eye being examined using the focal length f', the vertex distance VD, and the formula described within the step frame. The formula for calculating the image position S'' of the eye being examined uses the lens formula (1 / a + 1 / b = 1 / f) to determine where the image of the eye being examined E is formed during a simulated near vision test.

[0041] Step 335h calculates the distance test distance L' of the eye image from the position of the eye image using the position of the eye image S'', the vertex distance VD, the distance test distance FD, and the formula described in the step frame. The formula for calculating the distance test distance L' of the eye image is (FD - VD), where (FD - VD) is the position of the spectacle lens, and further takes into account the position of the eye image due to the spherical lens inserted during the simulated near vision test. The distance test distance L' of the eye image is approximately 5m when the distance corrective refractive power D is D = 0 (emmetropic eye), L' > 5m when D > 0 (hyperopic eye), and L' < 5m when D < 0 (myopic eye).

[0042] Step 335i calculates the near-eye inspection distance ratio h' with respect to the viewing angle considered to be the true value, using the near-eye inspection distance ratio h and the formula described within the step frame.

[0043] Step 335j calculates the drawing magnification β, which is the size magnification of the target M displayed at the distance examination distance FD, using the distance examination distance L' of the eye image being examined, the near examination distance ratio h', the distance examination distance FD, and the formula described in the step frame. This drawing magnification β is the magnification that corrects the change in the apparent size of the target caused by the spherical lens inserted during the simulated near vision test to the true size of the target. For example, the drawing magnification β is approximately 1 when the distance corrective refractive power D is D = 0 (emmetropic eye), β < 1 (reduced drawing) when D > 0 (hyperopia), and β > 1 (enlarged drawing) when D < 0 (myopia).

[0044] [Process flow until the start of simulated close-up inspection (Figures 9 and 10)] Figure 9 shows the process flow from preparation to the start of simulated close-up inspection.

[0045] Step S1 is a pseudo near vision examination preparation step. After determining the distance correction refractive power through a distance vision examination, the process proceeds to the pseudo near vision examination. In this distance vision examination, with the visual target M presented at a position 5 m from the test eye E, the refractive power within the examination window 114 of the refractometer head 100 is adjusted so that the test eye E can obtain a desired visual acuity value.

[0046] Step S2 is a near vision examination distance setting step, in which the examiner 3 sets the near vision examination distance through an input operation. Specific near vision examination distances include distances such as "1 m", "50 cm", "40 cm", "33.3 cm", etc.

[0047] Step S3 is an optical member set control step, which performs control to set a selected spherical lens (optical member) at the position of the examination window 114 of the refractometer head 100. Here, the spherical lens is selected based on the diopter addition value Dadd obtained by adding the second diopter D2 adjusted to the distance correction refractive power to the first diopter D1 adjusted to the set near vision examination distance. When the distance correction refractive power D is D = 0 (emmetropia) and the near vision examination distance is 40 cm, a -2.5 D spherical lens is set at the position of the examination window 114. When the distance correction refractive power D is D = +10 D (hyperopia) and the near vision examination distance is 40 cm, a +7.5 D (= +10 D - 2.5 D) spherical lens is set at the position of the examination window 114. When the distance correction refractive power D is D = -10 D (myopia) and the near vision examination distance is 40 cm, a -12.5 D (= -10 D - 2.5 D) spherical lens is set at the position of the examination window 114.

[0048] Step S4 is a convergence stimulus addition step. When performing a pseudo near vision examination with the spherical lens set, control is performed to change the convergence angle when viewing the visual target M with binocular vision in accordance with the near vision examination distance set in step S2.

[0049] Figure 10 is an explanatory diagram showing the change in convergence angle accompanying the transition from distance vision testing to pseudo-near vision testing. Step S4 uses prisms 124, 124 provided on a pair of measuring heads 105, 105 of the refractor head 100 to refract the first optical path A1 into the second optical path A2, thereby deflecting and adding convergence stimulation to the left eye EL and right eye ER. The prism amount α, which represents the degree of deflection by the prisms 124, 124 at this time, can be calculated by the following formula. α = [{(PD / 2) / ND} - {(PD / 2) / FD}] × 100 [Δ] PD: Interpupillary distance [mm] FD: Distance test distance [mm] ND: Near test distance [mm] Note that the prism diopter Δ is (h / 1)Δ when a deviation of h cm occurs at a distance of 1 m from the prism. For example, the prism diopter Δ is 1Δ when a deviation of 1 cm occurs at a distance of 1 m. The distance test distance FD is 5000 mm (5 m). The near test distances ND are, for example, ND1 is 1000 mm (1 m), ND2 is 500 mm (50 cm), ND3 is 400 mm (40 cm), and ND4 is 333 mm (33.3 cm).

[0050] Step S5 is a target drawing magnification change step, in which the drawing magnification β of the target M displayed on the target presentation device 200 is changed so that it appears the same size as when viewing a near-vision chart placed at the actual near-vision distance with distance refractive power corrected. That is, in step S5, when a simulated near-vision test is performed by setting a spherical lens at the position of the eye examination window 114, the magnification of the target M displayed on the target presentation device 200 is changed to the drawing magnification β calculated by the drawing magnification calculation unit 335. In Embodiment 1, the drawing magnification β is shown as being calculated by the drawing magnification calculation unit 335, but the drawing magnification β determined in advance by the distance corrected refractive power and the near-vision test distance may be stored and set as a drawing magnification table. If a drawing magnification table is stored and set, the drawing magnification β is read from the distance corrected refractive power, the near-vision test distance and the drawing magnification table, and the size of the target M is changed by the drawing magnification β.

[0051] Step S6 is the pseudo-near-vision test start step. Here, the flow leading up to the start of the pseudo-near-vision test in step S6 is shown as an example following the setting of the near-vision test distance in step S2, followed by optical component set control (step S3) → convergence stimulus addition control (step S4) → target drawing magnification change control (step S5). However, the flow leading up to the start of the pseudo-near-vision test in step S6 is not limited to the order shown in Figure 9 (S3 → S4 → S5) after the near-vision test distance is set in step S2, and the control order is not restricted.

[0052] [Background Technology of Visual Acuity Tests (Figures 11 and 12)] Distance vision tests are distance vision tests in which the tester looks at Landolt rings (thick circles with a portion cut out) or visual acuity charts with letters arranged on them with one eye at a time from a distance of 5m, and checks how large the object can be seen.

[0053] The Landolt ring used in distance vision tests is a circle with a diameter of 7.5 mm and a thickness of 1.5 mm, with a 1.5 mm gap between the circles. When this Landolt ring is viewed from a distance of 5 m, the angle between the two points (the gap) and the eye being tested is 1 min (1 / 60 degree), and the visual acuity at this point is defined as "1.0". In distance vision tests, the visual acuity value is the reciprocal of the smallest discriminable visual angle (1 / visual angle). For example, if the angle is 2 min, the visual acuity is 0.5, and if it is 0.5 min, the visual acuity is 2.0.

[0054] In contrast to the distance vision test described above, the near vision test involves measuring near vision by placing a real (paper, etc.) visual acuity chart at a near vision test distance, such as 30 cm or 40 cm, from the eye being examined (see Figure 7). The near vision measurement obtained from this near vision test is used to check how well one can see things up close, to determine the refractive power for prescribing reading glasses, to investigate the causes of eye strain, to observe the progress of visual development in children, and to judge suitability for occupations.

[0055] Regarding this near vision test, instead of the method shown in Figure 7, which involves placing a visual acuity chart at the actual near vision distance, a method has been proposed in Patent Document 1 to perform a pseudo-near vision test by using a visual target presented at the distance vision test distance as a pseudo-near vision target. This pseudo-near vision test is performed by placing an optical component (spherical lens) that adds an accommodative stimulus in front of the eye being examined. Here, an accommodative stimulus refers to a visual stimulus that requires the eye being examined to focus on an object in front of it.

[0056] However, the device proposed in Patent Document 1, when performing a simulated near vision test, causes the apparent size of the target presented at the distance vision test distance to change because the spherical lens is positioned in an anterior position different from the pupil position of the eye being examined. For this reason, the device proposed in Patent Document 1 cannot perform a near vision test with the same accuracy (target size) as a test using an actual near vision chart. The reason why the apparent size of the target presented at the distance vision test distance changes when a distance vision test is performed with a spherical lens positioned different from the pupil position of the eye being examined will be explained below.

[0057] Figure 11(a) shows the visual angle when viewing the gap in a Landolt ring 5 m away from the eye being examined. Figure 11(b) shows the change in the visual angle when viewing the Landolt ring with spectacle lenses (convex lenses for hyperopia correction) placed in front of the eye at a vertex distance VD from the eye being examined. When viewing the Landolt ring with spectacle lenses, as shown in Figure 11(b), the virtual image I' of the eye being examined is formed at a position further than 5 m away from the Landolt ring due to the insertion of the spectacle lenses. Therefore, the visual angle of the gap in the Landolt ring is smaller when viewing the Landolt ring from the position of the virtual image I' of the eye being examined with spectacle lenses inserted (Figure 11(b)) than when viewing the Landolt ring from the position of the real image I of the eye being examined without spectacle lenses (Figure 11(a)). Thus, when viewing the Landolt ring with spectacle lenses inserted, the visual angle of the gap in the Landolt ring changes.

[0058] Figure 12 shows the change in visual angle when an spectacle lens (a +10D convex lens) is placed at a distance VD (12 mm) from the corneal apex of the eye being examined, and the gap in the Landolt ring is viewed. When the Landolt ring is viewed at a distance of 5 m without the spectacle lens, the visual angle of the gap t is θ. When the Landolt ring is viewed from the virtual image I' of the eye with the spectacle lens in place, the visual angle of the gap t becomes θ' (<θ), indicating a decrease in the visual angle. In this case, the virtual image I' of the eye is not formed at a distance of 5 m from the Landolt ring, but at a distance of (distance vision test distance FD + eye image position S' - distance VD) from the Landolt ring. When the spectacle lens is placed at a distance VD from the eye being examined, in order to obtain the same visual angle θ' of the gap in the Landolt ring as the visual angle θ when the spectacle lens is not in place, the gap in the Landolt ring needs to be enlarged from gap t to gap T.

[0059] Thus, the change in the gap of the Landolt ring from gap t to gap T is due to the power (magnification) of the spectacle lens. Therefore, if the spectacle lens placed in front of the eye under examination is a convex lens system, the positive power causes the Landolt ring R' (virtual image) seen through the spectacle lens to appear larger than the Landolt ring R (real image) seen without the spectacle lens. On the other hand, if the spectacle lens placed in front of the eye under examination is a concave lens system, the negative power causes the Landolt ring seen through the spectacle lens to appear smaller than the Landolt ring seen without the spectacle lens, the opposite of the convex lens system.

[0060] [Simulated Near Vision Test Effect (Figure 9)] The appearance of the Landolt ring presented at the distance vision test distance changes depending on whether or not the above spectacle lens is present. The same can be said for simulated near vision tests performed by placing a spherical lens in front of the eye E at a vertex distance VD. The inventor focused on the fact that when performing a simulated near vision test, the size of the target changes when the target is viewed through a spherical lens set in front of the eye E at a vertex distance VD, and invented an optometry device 1 that eliminates the effect of inserting a spherical lens.

[0061] In other words, when performing a simulated near vision test on the eye E under examination, the procedure proceeds from step S1 to step S2, which are preparation steps for the simulated near vision test shown in Figure 9. In step S2, the near vision test distance is set arbitrarily. In step S3, a spherical lens selected to match the set near vision test distance and the distance vision correction power of the eye E under examination is set in the position of the eye examination window 114 of the refractor head 100. In the next step S4, a convergence stimulus is applied to the eye E under examination with a prism amount α that matches the set near vision test distance. In the next step S5, the drawing magnification β of the target M displayed on the target presentation device 200 is changed to match the set near vision test distance and distance vision correction power.

[0062] Thus, when performing a simulated near vision test on the eye E under examination, the optical component set control unit 333 selects a spherical lens that matches the set near vision test distance and distance corrective refractive power, and controls the setting of the selected spherical lens in the eye examination window 114 of the refractor head 100. The target drawing magnification changing unit 336 then controls the drawing magnification β of the target M displayed on the target presentation device 200 so that, when performing a simulated near vision test with the spherical lens set, the target appears to be the same size as when viewing a near vision chart placed at the actual near vision distance with distance refractive power corrected. Therefore, when performing a simulated near vision test with the spherical lens set, the eye examination device 1 can perform a near vision test with the same accuracy as a test using an actual near vision chart by changing the drawing magnification β of the displayed target M to eliminate the effect of inserting the spherical lens.

[0063] For example, the diopter D of the spherical lens set in the eye examination window 114 will be a -2.50D spherical lens to provide accommodative stimulation when the eye E being examined is emmetropic and the set near vision examination distance ND is "40 cm". The target drawing magnification changing unit 336 then changes the size of the displayed target M to a drawing magnification β that eliminates the effect of inserting the -2.50D spherical lens. Therefore, when the eye E being examined is emmetropic, near vision examination can be performed with the same accuracy as an examination using an actual near vision chart.

[0064] For example, if the spherical lens set in the ophthalmography window 114 has a distance corrective refractive power of +10D (hyperopia), and the near vision test distance ND is "40cm", the diopter D will be +7.50D, which is the sum of the accommodative stimulation lens -2.50D and the corrective lens +10D. Therefore, the size of the visual target M displayed on the visual target presentation device 200 is changed to a size determined by the drawing magnification β (<1) that eliminates the magnification effect caused by inserting a +7.5D convex lens. Thus, if the eye being examined E is hyperopic, near vision testing can be performed with the same accuracy as testing using an actual near vision chart.

[0065] For example, if the spherical lens set in the ophthalmography window 114 has a distance corrective refractive power of -10D (myopia) and the near vision test distance ND is "40cm", the diopter D will be -12.50D, which is the sum of the accommodative stimulation lens (-2.50D) and the corrective lens (-10D). Therefore, the size of the target M displayed on the target presentation device 200 is changed to a size determined by the drawing magnification β (>1) that eliminates the effect of inserting a -12.5D concave lens. Thus, if the eye being examined E is myopic, near vision testing can be performed with the same accuracy as testing using an actual near vision chart.

[0066] [Arbitrary Setting Function for Near Vision Testing Distance] Japanese Patent Publication No. 2016-10679 (hereinafter referred to as "Patent Document 2") proposes a target presentation device that can perform both distance vision and near vision tests by changing the testing distance by driving a single display that displays the target inside the device. However, in the device proposed in Patent Document 2, the near vision testing distance to the near vision target is limited to one location, and it is not possible to place the near vision target at an arbitrary position.

[0067] In contrast, the eye examination device 1 of Embodiment 1 employs a configuration that includes a near-vision examination distance setting unit 332 and an optical element set control unit 333. The near-vision examination distance setting unit 332 can be set to any near-vision examination distance when performing a simulated near-vision examination. When performing a simulated near-vision examination, the optical element set control unit 333 selects a spherical lens (optical element) according to the near-vision examination distance set by the near-vision examination distance setting unit 332 and controls the setting of the selected spherical lens at the position of the eye examination window 114 of the refractor head 100.

[0068] Therefore, when the set near vision testing distance is "1 m", a simulated near vision test with a near vision testing distance of 1 m can be performed by selecting a -1.00D spherical lens and controlling it to be set in the position of the eye examination window 114. When the set near vision testing distance is "50 cm", a simulated near vision test with a near vision testing distance of 50 cm can be performed by selecting a -2.00D spherical lens and controlling it to be set in the position of the eye examination window 114. When the set near vision testing distance is "40 cm", a simulated near vision test with a near vision testing distance of 40 cm can be performed by selecting a -2.50D spherical lens and controlling it to be set in the position of the eye examination window 114. When the set near vision testing distance is "33.3 cm", a simulated near vision test with a near vision testing distance of 33.3 cm can be performed by selecting a -3.00D spherical lens and controlling it to be set in the position of the eye examination window 114.

[0069] Therefore, in the optometry device 1 of Embodiment 1, the near vision test distance to the simulated near vision target can be arbitrarily set by the diopter of the spherical lens set at the position of the optometry window 114. Furthermore, when the subject 2 performs the visual acuity test alone in a remote examination, the near vision test distance can be set to any position by remote operation by the examiner 3 to set the near vision test distance setting unit 332. Moreover, when the subject 2 performs the visual acuity test alone in a remote examination, the subject 2 can set the near vision test distance to the near vision test distance setting unit 332 by inputting the information themselves.

[0070] [Effects of the eye examination device] The eye examination device 1 of Embodiment 1 can achieve the following effects.

[0071] (1) The optometry device 1 comprises an examination unit having an optometry window 114 for observing a target M with the eye to be examined E, a target presentation device 200 for presenting the target M to the eye to be examined at a position of a first examination distance, and a control unit 330 for controlling each part of the device. The examination unit sets an optical member in the optometry window 114 located in front of the eye to be examined E, which is used to simulate the use of the target M presented at the first examination distance as a target presented at a second examination distance shorter than the first examination distance. When the control unit 330 sets the optical member and performs a simulated refractive power test, it has a target drawing magnification changing unit 336 that changes the drawing magnification β of the target M displayed on the target presentation device 200 to a magnification that suppresses changes in the apparent size of the target M presented at the first examination distance. This optometry device 1 can prevent a decrease in examination accuracy caused by a change in the apparent size of the visual target presented at the first examination distance when an optical element is set and a simulated refractive power test is performed.

[0072] (2) When an optical element is set and a simulated refractive power test is performed, the target drawing magnification β of the target M displayed on the target presentation device 200 is changed to a magnification that makes the target appear to be the same size as when viewing a target placed at the second test distance with distance refractive power corrected. When an optical element is set and a simulated refractive power test is performed, the optometry device 1 can perform a refractive power test with the same accuracy (size of the target) as a test using a target placed at the second test distance.

[0073] (3) The first examination distance is the distance examination distance for performing a distance vision test of the refractive power of the eye being examined. The second examination distance is the near vision examination distance for performing a near vision test of the refractive power of the eye being examined. The examination unit sets an optical component, which simulates a near vision target presented at the near vision examination distance, at the position of the eye examination window 114 located in front of the eye being examined E. When the optical component is set and a simulated near vision test is performed, the target drawing magnification change unit 336 changes the drawing magnification β of the target M displayed on the target presentation device 200 to a magnification that makes it appear the same size as when viewing a near vision chart placed at the actual near vision distance with distance refractive power corrected. When this eye examination device 1 sets the optical component and performs a simulated near vision test, it can perform a near vision test with the same accuracy (size of the target) as a conventional test performed by placing a near vision chart at the actual near vision examination distance.

[0074] (4) The control unit 330 includes a near-vision testing distance setting unit 332 and an optical element set control unit 333. The near-vision testing distance setting unit 332 can be set to any near-vision testing distance when performing a simulated near-vision test. The optical element set control unit 333, when performing a simulated near-vision test, selects an optical element that provides an accommodative stimulus corresponding to the set near-vision testing distance and controls the setting of the selected optical element at the position of the eye examination window 114 of the refractor head 100. This eye examination device 1 allows the near-vision target to be placed at any near-vision testing distance when the subject 2 performs a simulated near-vision test by themselves in a remote examination or the like.

[0075] (5) The control unit 330 has a distance corrective refractive power setting unit 331 that sets the distance corrective refractive power of the eye E being examined. When performing a simulated near vision test, the optical component set control unit 333 selects an optical component that matches the set near vision test distance and distance corrective refractive power, and controls the setting of the selected optical component at the position of the eye examination window 114 of the refractor head 100. When performing a simulated near vision test of an eye E being examined that requires distance correction, this eye examination device 1 can set an appropriate optical component that matches the near vision test distance and distance corrective refractive power at the position of the eye examination window 114 of the refractor head 100.

[0076] (6) The optical element is a spherical lens. The optical element set control unit 333 sets a spherical lens with a diopter sum value Dadd, which is obtained by adding a second diopter D2, which is matched to the distance corrective refractive power, to a first diopter D1, which is matched to the set near vision examination distance, at the position of the eye examination window 114 of the refractor head 100. When performing a simulated near vision examination, this eye examination device 1 can set spherical lenses with various diopters that match both the near vision examination distance and the distance corrective refractive power, while reducing the number of lenses compared to when spherical lenses are prepared separately for the near vision examination distance and the distance corrective refractive power.

[0077] (7) The inspection unit is a refractor head 100 that incorporates multiple lens discs, each having multiple spherical lenses arranged in a circular pattern along the outer peripheral region of a disc shape, and each of the multiple lens discs 131, 132, and 133 is rotatable. The optical component set control unit 333 sets the diopter addition value Dadd by the spherical lens set at the position of the eye examination window 114 of the refractor head 100, by controlling the rotational drive of the lens discs 131, 132, and 133, either individually or in combination. When performing a simulated near vision test by setting a spherical lens, this eye examination device 1 can easily set a spherical lens with the required diopter value at the position of the eye examination window 114 of the refractor head 100 simply by controlling the rotational drive of the lens discs 131, 132, and 133.

[0078] (8) The control unit 330 has a convergence angle changing control unit 334 that, when setting an optical element and performing a simulated near vision test, controls the convergence angle when viewing the visual target M with binocular vision to match the near vision test distance set by the near vision test distance setting unit 332. When setting an optical element and performing a simulated near vision test, this eye examination device 1 can provide the eye under examination E with an appropriate convergence stimulus that matches the near vision test distance.

[0079] (9) The control unit 330 has a drawing magnification calculation unit 335 that calculates the drawing magnification β of the target M displayed on the target presentation device 200 using the distance corrective refractive power D, the vertex distance VD, the near examination distance ND, and the distance examination distance FD. The target drawing magnification changing unit 336 changes the drawing magnification of the target M displayed on the target presentation device 200 to the drawing magnification β calculated by the drawing magnification calculation unit 335 when an optical member is set and a simulated near examination is performed. This optometry device 1 can appropriately change the size of the target M displayed on the target presentation device 200 according to the drawing magnification β calculated according to the distance corrective refractive power D which differs depending on the eye being examined E and the near examination distance ND which differs depending on the purpose of the examination. <Embodiment 2>

[0080] Embodiment 2 is an example in which, when performing a simulated near vision test, the drawing magnification β of the target M is corrected using only the lens power of the simulated near vision lens added to present a virtual image of the target at the near vision position, without taking into account the distance vision correction power as in Embodiment 1.

[0081] The overall configuration of the apparatus in Embodiment 2 and the detailed configuration of the measuring head are the same as the overall configuration of the apparatus in Embodiment 1 (Figure 1) and the detailed configuration of the measuring head (Figures 2 to 5), so their illustration and description are omitted.

[0082] [Detailed Configuration of Controller Device (Figure 13)] Figure 13 shows a block diagram of the control system centered on the controller device 300 of Embodiment 2. The controller device 300 is generally composed of an operation main unit 310, a monitor unit 320, a control unit 330', and a storage unit 340. The operation main unit 310, the monitor unit 320, and the storage unit 340 have the same configuration as in Embodiment 1.

[0083] The control unit 330' includes a near-vision inspection distance setting unit 332, an optical element set control unit 333', a convergence angle change control unit 334, a drawing magnification table setting unit 337, and a target drawing magnification change unit 336'. In other words, the control unit 330' of Embodiment 2 omits the far-vision corrective refractive power setting unit 331 of Embodiment 1, and replaces the drawing magnification table setting unit 337 with the drawing magnification calculation unit 335 of Embodiment 1. Furthermore, the control unit 330' changes some of the control processing contents of the optical element set control unit 333' and the target drawing magnification change unit 336' from Embodiment 1.

[0084] The close-range inspection distance setting unit 332 can be set to any close-range inspection distance (an example of a second inspection distance) when performing a simulated close-range inspection. Any close-range inspection distance can be, for example, 1 m, 50 cm, 40 cm, 33.3 cm, etc.

[0085] The optical component set control unit 333' sets a spherical lens (optical component) that simulates a near-vision target presented at the near-vision testing distance (5 m) as a near-vision target presented at the near-vision testing distance, at the position of the eye examination window 114 located in front of the eye E being examined. In other words, the optical component set control unit 333' of Embodiment 2 selects a spherical lens (hereinafter referred to as the "simulated near-vision lens") consisting only of a first diopter D1 matched to the near-vision testing distance. Therefore, the optical component set control unit 333' of Embodiment 2 differs from the optical component set control unit 333 of Embodiment 1 in that it sets the spherical lens without considering a second diopter D2 matched to the distance correction refractive power.

[0086] Similar to Embodiment 1, the convergence angle change control unit 334 controls the convergence angle when viewing the target M with binocular vision when setting the optical element and performing a simulated near-vision test, to match the near-vision test distance set by the near-vision test distance setting unit 332.

[0087] The drawing magnification table setting unit 337 sets a drawing magnification table that shows the relationship between the diopter of the pseudo-near-vision lens added to make the target visible when placed at the near-vision examination distance, and the pseudo-near-vision chart magnification that suppresses the change in apparent size caused solely by the pseudo-near-vision lens. The diopter of the pseudo-near-vision lens corresponds to the value of the first diopter D1, which is matched to the near-vision examination distance in Embodiment 1. The pseudo-near-vision chart magnification corresponds to the value of the drawing magnification β of the target M displayed on the target presentation device 200 in Embodiment 1. A detailed explanation of the drawing magnification table will be given later.

[0088] The target drawing magnification changing unit 336' changes the drawing magnification β of the target M displayed on the target presentation device 200 to the pseudo-near chart magnification obtained using the diopter of the pseudo-near lens and the drawing magnification table when a pseudo-near vision test is performed with a pseudo-near vision lens set. In other words, when a pseudo-near vision test is performed, the target drawing magnification changing unit 336 of Embodiment 1 obtains drawing magnification information to change the size of the target M by the calculation process shown in Figure 8. In contrast, when a pseudo-near vision test is performed, the target drawing magnification changing unit 336' of Embodiment 2 obtains drawing magnification information to change the size of the target M by referring to the drawing magnification table T shown in Figure 14, for example, and reading the pseudo-near chart magnification corresponding to the diopter of the pseudo-near vision lens.

[0089] [Details of the drawing magnification table (Figure 14)] Figure 14 shows an example of a drawing magnification table T set in the drawing magnification table setting unit 337. The details of the drawing magnification table T will be explained below.

[0090] The drawing magnification table T is a table that can be set by not taking distance vision correction into consideration. The drawing magnification table T in Figure 14 shows the chart magnification based on the add power when performing a simulated near vision test, where the distance VD from the corneal apex to the spectacle lens is 12 mm, the distance from the corneal apex to the point of ocular rotation is 13 mm, the interpupillary distance PD is 64 mm, and the distance vision test distance FD is 5 m.

[0091] As shown in Figure 14, the diopter D of the pseudo-near-vision lens is set in 13 types with intervals of 0.25D from -1.00D (near-vision examination distance ND: 1m) to -4.00D (near-vision examination distance ND: 25cm). Therefore, the degree of freedom in setting the near-vision examination distance ND includes -2.00D (near-vision examination distance ND: 50cm), -2.50D (near-vision examination distance ND: 40cm), -3.00D (near-vision examination distance ND: 33.3cm), etc. This is because the diopter D of the spherical lens set at the position of the eye examination window 114 of the measuring head 105 is adjustable in intervals of 0.25D by using the spherical lens set individually or in combination.

[0092] The pseudo-near-vision chart magnification is calculated in advance for each of the 13 types of pseudo-near-vision lenses with a diopter D, using a predetermined calculation formula that includes the distance VD from the corneal apex to the spectacle lens, the interpupillary distance PD, the near-vision examination distance ND, the far-vision examination distance FD, etc. In other words, the calculation of the pseudo-near-vision chart magnification in Embodiment 2 is performed using a predetermined calculation formula that omits the "far-vision corrective refractive power D" shown in Figure 8, which is included in the calculation formula for the drawing magnification β of the target M in Embodiment 1.

[0093] Here, the near vision examination distance ND is determined by the settings of the subject and examiner in the simulated near vision examination, but the calculated value of the simulated near vision chart magnification also changes if the distance VD from the corneal apex to the spectacle lens, the interpupillary distance PD, and the distance vision examination distance FD are different. The distance VD from the corneal apex to the spectacle lens varies by race. For example, the average value for Westerners is 13.75 mm. Also, the distance VD differs depending on whether or not contact lenses are prescribed. The interpupillary distance PD differs depending on individual differences in the subject such as age, gender, and physique. The distance vision examination distance FD differs from country to country. In Japan, the distance vision examination distance FD is 5 m, but in the United States, for example, it is 6 m. Therefore, it is preferable for the drawing magnification table setting unit 337 to prepare drawing magnification tables to match these different distances VD, PD, and FD.

[0094] The distance VD from the corneal apex to the spectacle lens is the most affected by changes in the calculated value of the pseudo-near-vision chart among these distances VD, PD, and FD. For this reason, it is preferable to prepare a drawing magnification table for each distance VD from the corneal apex to the spectacle lens (e.g., VD = 12, VD = 13.75). In this case, the control unit 330' stores multiple drawing magnification tables for each distance VD in the storage unit 340 beforehand. Then, when performing a pseudo-near-vision test, the drawing magnification table setting unit 337 reads the drawing magnification table that matches the subject's distance VD from the storage unit 340 and sets it.

[0095] [Simulated Near Vision Test Operation (Figure 9)] The simulated near vision test in Embodiment 1 above inevitably becomes complicated due to the need to correct the target magnification by taking into account the distance vision correction power. In contrast, the inventors have found that in simulated near vision testing, the refractive power of the simulated near vision lens added to simulate the near vision distance position of a target presented at a distance distance is the main factor that changes the apparent size of the target. Therefore, Embodiment 2 is an optometry device that corrects the target magnification by only the amount of the simulated near vision lens added to present a virtual image at the near vision position, without taking into account the distance vision correction power, which has a small impact, in a simulated near vision test.

[0096] In other words, when performing a simulated near vision test on the eye E under examination, the procedure proceeds from step S1 to step S2, which are preparation steps for the simulated near vision test shown in Figure 9. In step S2, the near vision test distance is selected and set from 13 different options. In step S3, a simulated near vision lens with a diopter matched to the set near vision test distance is set in the eye examination window 114 of the refractor head 100. In the next step S4, a convergence stimulus is applied to the eye E under examination with a prism amount α matched to the set near vision test distance. In the next step S5, the drawing magnification β of the visual target M displayed on the visual target presentation device 200 is changed to the simulated near vision chart magnification matched to the diopter of the set simulated near vision lens.

[0097] Thus, when performing a simulated near vision test on the eye E under examination, the optical component set control unit 333' selects a spherical lens with a diopter that matches the set near vision test distance and controls the setting of the selected spherical lens as a simulated near vision lens at the position of the eye examination window 114 of the refractor head 100. Then, when performing a simulated near vision test with the simulated near vision lens set, the target drawing magnification change unit 336' refers to the drawing magnification table T and controls the setting of the drawing magnification β of the target M displayed on the target presentation device 200 to the simulated near vision chart magnification corresponding to the simulated near vision lens. Therefore, when performing a simulated near vision test with the simulated near vision lens set, the effect of the apparent change in the size of the target caused by inserting the simulated near vision lens is eliminated by changing the drawing magnification β of the target M displayed on the target presentation device 200 to the simulated near vision chart magnification.

[0098] For example, when performing a simulated near vision test, if the near vision test distance ND is set to "40 cm", the simulated near vision lens set in the ophthalmography window 114 will be a -2.50D spherical lens that provides accommodative stimulation. Therefore, the target drawing magnification changing unit 336' refers to the drawing magnification table T set in the drawing magnification table setting unit 337 and controls the drawing magnification β of the target M displayed on the target presentation device 200 to the simulated near vision chart magnification (1.030) corresponding to -2.50D. Thus, the effect of changing the apparent size of the target M by placing a -2.50D simulated near vision lens in front of the eye being examined E is eliminated. As a result, if the eye being examined E is emmetropic, the simulated near vision test can be performed with the same accuracy as a test using a real near vision chart. Furthermore, even in the case of eye E requiring distance vision correction, the pseudo-near vision test of Embodiment 2 reliably eliminates the influence of the apparent change in the size of the visual target due to the insertion of the pseudo-near vision lens, thereby enabling a pseudo-near vision test with high accuracy.

[0099] [Effects of the eye examination device] In the eye examination device of Embodiment 2, in addition to the effect of (1) of the eye examination device 1 of Embodiment 1, the following effects can be achieved.

[0100] (10) The target drawing magnification changing unit 336' changes the drawing magnification β of the target M displayed at the first test distance to a magnification that suppresses the change in apparent size caused only by the optical element added to make it appear as a target placed at the second test distance when an optical element is set and a simulated refractive power test is performed. This optometry device simplifies the calculation of the target magnification in a simulated refractive power test compared to Embodiment 1, which takes distance vision correction into consideration, by determining the magnification of the target M without depending on the subject's distance vision correction.

[0101] (11) The optical component is a spherical lens. The control unit 330' has a drawing magnification table setting unit 337 that sets a drawing magnification table T that shows the relationship between the diopter of the pseudo-near lens added to make the target visible to the target placed at the second examination distance and the pseudo-near chart magnification that suppresses the change in apparent size due to the pseudo-near lens alone. The target drawing magnification changing unit 336' changes the drawing magnification β of the target M displayed on the target presentation device 200 to the pseudo-near chart magnification obtained using the diopter of the pseudo-near lens and the drawing magnification table T when the pseudo-near lens is set and a pseudo-near examination is performed. When changing the magnification of the target M displayed at the distance distance, this optometry device can easily change the target magnification to the corrected magnification by obtaining the pseudo-near chart magnification using the diopter of the pseudo-near lens and the drawing magnification table, thereby omitting calculation processing.

[0102] The above description is based on the drawings of the ophthalmic device of Embodiment 1 and the ophthalmic device of Embodiment 2. However, the specific configuration of the ophthalmic device of this disclosure is not limited to the configurations shown in Embodiment 1 and Embodiment 2. Modifications and additions to the design of the ophthalmic device of this disclosure are permitted as long as they do not depart from the gist of the invention as described in each claim.

[0103] Embodiments 1 and 2 show examples in which a spherical lens is used as the optical element. However, the optical element is not limited to a spherical lens; for example, a liquid lens may be used in which the interface between water and oil in a container is used as the lens, and the focal length of the lens is adjusted by changing the shape of the interface by applying a voltage and adjusting the refractive index of light.

[0104] Embodiments 1 and 2 show examples of a refractor head 100 that incorporates multiple lens discs 131, 132, and 133, each having multiple spherical lenses arranged in a circular pattern along the outer peripheral region of a disc shape, and each disc is driveable by rotational drive control. However, the inspection unit is not limited to the refractor head of Embodiment 1, and may be, for example, a manual subjective refraction testing device in which the spherical lenses can be manually replaced.

[0105] Embodiments 1 and 2 show examples in which the optometry device is composed of a refractor head 100, a target presentation device 200, and a controller device 300, each consisting of independent devices. However, the optometry device may also be composed of a composite device that integrally includes, for example, an optometry unit capable of setting an optical element at a position away from the eye to be examined, a target display unit having a target presentation function, and a control unit.

[0106] Embodiments 1 and 2 show examples in which a general-purpose personal computer is used as the controller device 300. However, the controller device is not limited to the example in which a personal computer is used; for example, a dedicated controller for operating the refractor head and target presentation device may be used. When a dedicated controller is used, it is operated using a dial, buttons, or a touch panel on the screen.

[0107] Embodiments 1 and 2 show examples where the first examination distance is set to the distance vision examination distance (5 m) used for distance vision testing of the refractive power of the eye under examination. However, the first examination distance is not limited to the distance vision examination distance, and may be set to a distance longer than 5 m or shorter than 5 m in response to a refractive power test requirement that presents a visual target at a distance sufficiently far from the eye under examination.

[0108] Embodiments 1 and 2 show examples where the second examination distance is set to a near-vision examination distance, assuming a near-vision test at a distance of several tens of centimeters from the subject's eye. However, the second examination distance is not limited to the near-vision examination distance, and may be set to approximately 3 meters, assuming an indoor setting, or to an intermediate examination distance of approximately 2 to 4 meters, which is between the near-vision and far-vision distances.

[0109] Embodiments 1 and 2 show an example in which the examination unit sets an optical component that operates as a near-vision target, which is presented at the distance examination distance, in a position in the eye examination window 114 located in front of the eye E being examined. However, the examination unit is not limited to the example in which an optical component that operates as a near-vision target is set at the eye examination window; an example in which an optical component that operates as an intermediate-distance target is set at the eye examination window may also be used.

[0110] Embodiments 1 and 2 show examples in which the target drawing magnification changing unit 336 and target drawing magnification changing unit 336' change the drawing magnification β of the target M displayed on the target presentation device 200 when performing a pseudo-near-vision test using a near-vision test distance shorter than the far-vision test distance. However, the target drawing magnification changing unit is not limited to pseudo-near-vision tests, and may also be used as an example in which the drawing magnification of the target displayed on the target presentation device changes when performing a pseudo-refractive power test using a second test distance shorter than the first test distance, which is not called a near-vision test.

[0111] The optometry apparatus of this disclosure may be appropriately combined with other components as long as it does not contradict them. The optometry apparatus of this disclosure may be described in whole or in part as follows. However, the content is not limited to the following. 1. An optometry apparatus comprising: an examination unit having an examination window for observing a target with the eye to be examined; a target presentation device for presenting a target to the eye to be examined at a position of a first examination distance; and a control unit for controlling each part of the device, wherein the examination unit sets an optical member at the position of the examination window located in front of the eye to be examined, which simulates operating the target presented at the first examination distance as a target presented at a second examination distance shorter than the first examination distance; and the control unit has a target drawing magnification changing unit that, when the optical member is set and a simulated refractive power test is performed, changes the drawing magnification of the target displayed on the target presentation device to a magnification that suppresses changes in the apparent size of the target presented at the first examination distance. 2.1 The optometry apparatus described above, wherein the target drawing magnification changing unit, when the optical member is set and a simulated refractive power test is performed, changes the drawing magnification of the target displayed on the target presentation device to a magnification that makes the target appear to be the same size as when viewing a target placed at the second test distance with distance refractive power corrected. 3.2 The optometry device is characterized in that, the first examination distance is a distance examination distance for performing a distance vision test of the refractive power of the eye to be examined, the second examination distance is a near vision test distance for performing a near vision test of the refractive power of the eye to be examined, the examination unit sets an optical member that simulates the target presented at the distance examination distance as a near vision target presented at the near vision examination distance, at the position of the optometry window positioned in front of the eye to be examined, and the target drawing magnification changing unit, when the optical member is set and a simulated near vision test is performed, changes the drawing magnification of the target displayed on the target presentation device to a magnification that makes it appear the same size as when viewing a near vision chart placed at the actual near vision distance with distance refractive power corrected.4.3 An optometry device characterized in that the control unit includes a near-vision distance setting unit that can set the near-vision distance to any near-vision distance when performing the simulated near-vision test, and an optical element set control unit that, when performing the simulated near-vision test, selects an optical element that provides an accommodative stimulus in accordance with the set near-vision distance and controls the setting of the selected optical element at the position of the eye examination window of the examination unit. 5.4 An optometry device characterized in that the control unit includes a distance corrective refractive power setting unit that sets the distance corrective refractive power of the eye to be examined, and the optical element set control unit, when performing the simulated near-vision test, selects an optical element in accordance with the set near-vision distance and distance corrective refractive power and controls the setting of the selected optical element at the position of the eye examination window of the examination unit. 6.4 or 5: An optometric apparatus, wherein the optical element is a spherical lens, and the optical element set control unit sets the spherical lens at the position of the eye examination window of the examination unit, with a diopter sum value obtained by adding a second diopter, which is matched to the corrective refractive power for distance, to a first diopter, which is matched to the set near examination distance. 7.6: An optometric apparatus, wherein the examination unit incorporates a plurality of lens discs, each having a plurality of spherical lenses arranged in a circular pattern along the outer peripheral region of a disc shape, and each of the plurality of lens discs is a rotatable refractor head, and the optical element set control unit sets the diopter sum value obtained by the spherical lens set at the position of the eye examination window of the refractor head by controlling the rotational drive of the lens discs, either individually or in combination. An optometry device according to any one of paragraphs 8.4 to 8.7, characterized in that the control unit has a convergence angle changing control unit that, when setting the optical member and performing a simulated near vision test, controls the convergence angle when viewing the target with binocular vision to match the near vision test distance set by the near vision test distance setting unit.9. An optometric apparatus according to any one of paragraphs 9.3 to 8, wherein the control unit has a drawing magnification calculation unit that uses the distance corrective refractive power, the vertex distance, the near examination distance, and the distance examination distance to calculate the drawing magnification of the target displayed on the target presentation device, and the target drawing magnification changing unit changes the drawing magnification of the target displayed on the target presentation device to the drawing magnification calculated by the drawing magnification calculation unit when the optical member is set and a simulated near examination is performed. 10. An optometric apparatus according to 10.1, wherein the target drawing magnification changing unit changes the drawing magnification of the target displayed at the first examination distance to a magnification that suppresses the change in apparent size caused only by the optical member added to make the target appear to be placed at the second examination distance when the optical member is set and a simulated refractive power examination is performed. 11.10 The optometry apparatus, wherein the optical element is a spherical lens, the control unit has a drawing magnification table setting unit that sets a drawing magnification table representing the relationship between the diopter of a pseudo-near lens added to make the target visible to the target placed at the second examination distance and the pseudo-near chart magnification that suppresses the apparent size change caused solely by the pseudo-near lens, and the target drawing magnification changing unit changes the drawing magnification of the target displayed on the target presentation device to the pseudo-near chart magnification obtained using the diopter of the pseudo-near lens and the drawing magnification table when the pseudo-near lens is set and a pseudo-near examination is performed. Cross-reference of related applications

[0112] This application claims priority over Japanese Patent Application No. 2024-230801, filed with the Japan Patent Office on 26 December 2024, all of which disclosures are incorporated herein by reference in their entirety.

Claims

1. An optometry device comprising: an examination unit having an eye examination window for observing a target with the eye under examination; a target presentation device for presenting the target at a position of a first examination distance relative to the eye under examination; and a control unit for controlling each part of the device, wherein the examination unit sets an optical member at the position of the eye examination window positioned in front of the eye under examination to operate the target presented at the first examination distance as a target presented at a second examination distance shorter than the first examination distance; and the control unit has a target drawing magnification changing unit that, when the optical member is set and a simulated refractive power test is performed, changes the drawing magnification of the target displayed on the target presentation device to a magnification that suppresses changes in the apparent size of the target presented at the first examination distance.

2. An optometric apparatus according to claim 1, wherein the target drawing magnification changing unit, when the optical member is set and a simulated refractive power test is performed, changes the drawing magnification of the target displayed on the target presentation device to a magnification that makes the target appear to be the same size as when viewing a target placed at the second test distance with distance refractive power corrected.

3. An optometry device according to claim 2, wherein the first examination distance is a distance examination distance for performing a distance vision test of the refractive power of the eye to be examined, the second examination distance is a near vision examination distance for performing a near vision test of the refractive power of the eye to be examined, the examination unit sets an optical member for operating the target presented at the distance examination distance as a near vision target presented at the near vision examination distance, at the position of the optometry window positioned in front of the eye to be examined, and the target drawing magnification changing unit, when setting the optical member to perform a simulated near vision test, changes the drawing magnification of the target displayed on the target presentation device to a magnification that makes the target appear to be the same size as when viewing a near vision chart placed at the actual near vision distance with distance refractive power corrected.

4. An ophthalmic examination device according to claim 3, wherein the control unit comprises: a near-vision distance setting unit that can set the near-vision examination distance to any near-vision examination distance when performing the simulated near-vision examination; and an optical element setting control unit that, when performing the simulated near-vision examination, selects an optical element that provides an adjustment stimulus corresponding to the set near-vision examination distance and controls the setting of the selected optical element at the position of the ophthalmic examination window of the examination unit.

5. An optometry device according to claim 4, wherein the control unit has a distance corrective refractive power setting unit for setting the distance corrective refractive power of the eye to be examined, and the optical member set control unit, when performing the simulated near vision test, selects an optical member that matches the set near vision test distance and the distance corrective refractive power, and controls the setting of the selected optical member at the position of the eye examination window of the examination unit.

6. An optometry device according to claim 5, wherein the optical element is a spherical lens, and the optical element set control unit sets the spherical lens, which has a diopter sum value obtained by adding a second diopter, which is matched to the corrective refractive power for distance, to a first diopter, which is matched to the set near examination distance, at the position of the optometry window of the examination unit.

7. An optometry device according to claim 6, wherein the examination unit incorporates a plurality of lens discs having a plurality of spherical lenses arranged in a circular manner along the outer peripheral region of a disc shape, each of the plurality of lens discs being a rotatable refractor head, and the optical member set control unit sets the diopter sum value by the spherical lenses set at the position of the optometry window of the refractor head by the rotational drive control of the lens discs, either by the spherical lenses individually or in combination.

8. An optometry device according to claim 4, wherein the control unit has a convergence angle changing control unit that, when setting the optical member and performing a simulated near vision test, controls the convergence angle when viewing the target with binocular vision to match the near vision test distance set by the near vision test distance setting unit.

9. An optometry device according to any one of claims 3 to 8, wherein the control unit has a drawing magnification calculation unit that uses the distance corrective refractive power, the vertex distance, the near examination distance, and the distance examination distance to calculate the drawing magnification of the target displayed on the target presentation device, and the target drawing magnification changing unit changes the drawing magnification of the target displayed on the target presentation device to the drawing magnification calculated by the drawing magnification calculation unit when the optical member is set and a simulated near examination is performed.

10. An optometric apparatus according to claim 1, wherein the target drawing magnification changing unit, when setting the optical member and performing a simulated refractive power test, changes the drawing magnification of the target displayed at the first test distance to a magnification that suppresses the change in apparent size caused solely by the optical member added to make it appear as a target placed at the second test distance.

11. An optometry device according to claim 10, wherein the optical element is a spherical lens, the control unit has a drawing magnification table setting unit that sets a drawing magnification table representing the relationship between the diopter of a pseudo-near-vision lens added to make the target visible to the target placed at the second examination distance and the pseudo-near-vision chart magnification that suppresses the apparent size from changing solely due to the pseudo-near-vision lens, and the target drawing magnification changing unit, when the pseudo-near-vision lens is set and a pseudo-near-vision examination is performed, changes the drawing magnification of the target displayed on the target presentation device to the pseudo-near-vision chart magnification obtained using the diopter of the pseudo-near-vision lens and the drawing magnification table.

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