Red-green inspection device and red-green inspection method

Abstract

To provide a red-green inspection device and a red-green inspection method capable of improving inspection accuracy of a red-green inspection.SOLUTION: A red-green inspection device 1 of a simultaneously viewing type, includes a window frame 7. Inside the window frame 7, a first prism 11 and a second prism 13 having different colors are arranged such that bases thereof face each other.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a red-green tester and a red-green test method. [Background technology]

[0002] 2. Description of the Related Art Red-green examinations that utilize chromatic aberration have been known in the past and are performed as a final check in refraction examinations in ophthalmology. In the red-green test, the patient looks at red and green targets on an eye chart. If the targets appear evenly on the green and red backgrounds, the refractive correction is judged to be appropriate (full correction). If the red is clearly visible, the patient is judged to have insufficient correction of myopia (undercorrection) or excessive correction of hyperopia (overcorrection). If the green is clearly visible, the patient is judged to have overcorrection of myopia or undercorrection of hyperopia. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-190654 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is no JIS standard for the shape of the red and green targets (double squares, double circles, etc.) on vision charts, and the color tones of the red and green vary depending on the manufacturer of the vision chart.In addition, since the size of the targets is constant, the targets may be difficult to see depending on the subject's visual acuity, which may reduce the accuracy of the red-green test. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a red-green tester and a red-green test method that can improve the test accuracy of red-green tests. [Means for solving the problem]

[0005] The present invention is a simultaneous vision type red-green tester, which includes a window frame, and a first prism and a second prism disposed within the window frame with their bases facing each other.

[0006] The present invention is an alternating vision type red-green tester, which is provided with a window frame, and within the window frame, a first color filter for forming an image in the front of the subject's eye and a second color filter for forming an image in the back of the subject's eye are arranged.

[0007] The present invention is a red-green testing method in which a first prism for forming an image in front of the retina in the subject's eye and a second prism for forming an image behind the retina in the subject's eye are arranged within a window frame with their bases facing each other, the window frame is held in front of the subject's eyes, and a single visual target is simultaneously viewed by the subject, and it is determined which visual target is clearer, the visual target seen through the first prism or the visual target seen through the second prism. [Effects of the Invention]

[0008] According to the present invention, the inspection accuracy of the red-green inspection is improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a simultaneous vision type red-green inspector according to the present embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along plane II of FIG. [Figure 3] FIG. 1 is a diagram illustrating a red-green inspection using a red-green inspector. [Figure 4] FIG. 1 is a diagram schematically illustrating chromatic aberration in an eyeball. [Figure 5] FIG. 10 is a diagram showing the verification results of the measurement accuracy of a red-green inspector. [Figure 6] FIG. 1 is a perspective view of an ophthalmoscope-type red-green tester used in red-green testing. [Figure 7] FIG. 7 is a cross-sectional view taken along plane VII of FIG. 6. [Figure 8] FIG. 1 is a front view showing a red-green tester attached to an eye trial frame. [Figure 9] FIG. 1 is a perspective view of a simultaneous vision type red-green inspector according to the present embodiment. [Figure 10]FIG. 1 is a diagram illustrating a red-green inspection using a red-green inspector. DETAILED DESCRIPTION OF THE INVENTION

[0010] <First Embodiment> (Configuration of simultaneous red-green detector) Hereinafter, the first embodiment will be described with reference to the drawings. Fig. 1 is a perspective view of a simultaneous vision type red-green inspector 1 used in red-green inspection. As shown in Fig. 1, red-green inspector 1 includes a handheld red-green inspector main body 3, which includes a handle 5 and a window frame 7 fixed to the tip of handle 5. In the first embodiment, a first prism 11 and a second prism 13 are disposed in window frame 7.

[0011] Fig. 2 is a cross-sectional view taken along plane II in Fig. 1. Plane II is a plane that is perpendicular to the longitudinal direction of handle 5 and intersects with window frame 7, first prism 11, and second prism 13. As shown in FIG. 2, the first prism 11 and the second prism 13 are arranged in the window frame 7 so that the bases 11A and 13A face each other.

[0012] The first prism 11 has a first color for forming an image in front of the retina in the subject's eye. That is, the first prism 11 is a colorless transparent body, and a thin green filter 15 is attached to the first prism 11 as the first color filter. The second prism 13 has a second color filter for forming an image behind the retina in the subject's eye. That is, the second prism 13 is a colorless transparent body, and a thin red filter 17 is attached to the second prism 13 as the second color filter.

[0013] Alternatively, the first prism 11 may be made of a green transparent material for the first color, and the second prism 13 may be made of a red transparent material for the second color. In this case, the thin filters 15 and 17 can be omitted from the red-green inspector 1.

[0014] (Red-green inspection method) A red-green inspection method using the red-green inspector 1 will be described with reference to FIG. In FIG. 3, reference numeral 31 denotes the subject's eyeball. In a red-green test using the red-green tester 1, a corrective lens 32 is positioned in front of the eyeball 31, and the window frame 7 of this embodiment is positioned in front of the corrective lens 32. A first prism 11 and a second prism 13 are disposed in the window frame 7. The subject views a single optotype 33 in front of the window frame 7. The optotype 33 may be, for example, various characters such as hiragana written in black, a Landolt ring, or various images. A light source 34 is disposed behind the optotype 33.

[0015] In red-green inspection, the reference wavelength is generally set to 570 to 590 nm. The reference wavelength light C is light having a wavelength approximately midway between the upper limit and the lower limit of the wavelength within the range of visible light (FIG. 4). Filter 15 and filter 17 are formed so that one of them transmits light with a shorter peak wavelength and the other transmits light with a longer peak wavelength. Filter 15 and filter 17 are formed so that the difference between their respective peak wavelengths and the reference wavelength is approximately the same. Therefore, filter 15 is formed so that the peak wavelength is 530 to 550 nm, and filter 17 is formed so that the peak wavelength is 600 to 630 nm.

[0016] In Fig. 3, the distance L1 between the window frame 7 (the rear surfaces of the first prism 11 and the second prism 13) and the corneal vertex of the eyeball 31 is 1 to 1000 mm for the purpose of examination, and is preferably about 10 to 150 mm in reality. The distance L2 between the visual target 33 and the corneal vertex of the eyeball 31 is about 3 to 5 m, and in principle is 5 m at a distance.

[0017] The red-green test is an inspection method that utilizes chromatic aberration, and is used, for example, to adjust lenses for correcting myopia or hyperopia. When the subject views one visual target 33 in front of them through the window frame 7, the visual target 33G seen through the green first prism 11 has a short transmitted wavelength and is imaged in front of the retina 35 in the eye. In contrast, the visual target 33R seen through the red second prism 13 has a long transmitted wavelength and is imaged behind the retina 35 in the eye.

[0018] FIG. 4 is a diagram schematically showing chromatic aberration in the eyeball. A red-green test in the case where the eyeball 31 to be tested is a myopic eye will be described with reference to FIG. As shown in Figure 4(A), when a subject looks at one optotype 33, if the optotype 33G seen through the green first prism 11 and the optotype 33R seen through the red second prism 13 appear approximately even, the correction of refraction by the corrective lens 32 is appropriate (full correction). As shown in Figure 4(B), if the red optotype 33R appears more clearly than the green optotype 33G, the correction of refraction by the corrective lens 32 is insufficient (undercorrection). As shown in Figure 4(C), if the green optotype 33G appears more clearly than the red optotype 33R, the corrective lens 32 is determined to be overcorrected (overcorrection).

[0019] If the eyeball 31 being examined is farsighted, when the subject looks at one optotype 33, if the red optotype 33R is seen more clearly than the green optotype 33G, the correction by the corrective lens 32 is determined to be overcorrection. On the other hand, if the green optotype 33G is seen more clearly than the red optotype 33R, the correction by the corrective lens 32 is determined to be undercorrection. If the green target 33G and the red target 33R are seen almost equally, the correction state of the refraction of the corrective lens 32 is determined to be perfect correction, as in the case of myopia.

[0020] 3, light F emitted from light source 34 is refracted by first prism 11 and second prism 13. Of the light F that passes through first prism 11 and second prism 13, green light that passes through filter 15 and red light that passes through filter 17 are directed toward the eyeball. As a result, in a red-green test using red-green tester 1, red light and green light can be seen with one eyeball 31, and the red-green test can be performed simultaneously.

[0021] Furthermore, in a red-green test using red-green tester 1, filters 15 and 17 are provided separately from optotype 33. Therefore, in a red-green test using red-green tester 1, the test accuracy can be improved by changing the size of optotype 33 to the minimum visible size depending on the visual acuity of the subject, for example.

[0022] (Verification of measurement accuracy) Fig. 5 is a diagram showing the results of verifying the measurement accuracy of the red-green inspector 1. The vertical axis (D) in Fig. 5 represents diopters. The inventors verified the measurement accuracy of the red-green tester 1 using 31 dominant eyes of 31 healthy subjects who had no eye diseases other than refractive errors. After determining the provisional subjective refraction, a +1.00D fogging was performed, and lenses were added in increments of -0.125D until the most hyperopic power at which the highest logMAR value was achieved was determined, which was taken as the full correction value. Next, two types of red-green tests were performed, one with a transparent lens and one with a filter lens. The most hyperopic power at which red and green appeared equal was taken as the result of the red-green test, and this result was compared with the full correction value. The subjects were also asked which test was easier to answer, the transparent lens or the filter lens. Here, the transmission type is a method commonly used in conventional red-green tests, in which black targets on each of red and green colored screens are viewed using transmitted light placed behind the screens. The filter method uses a red-green detector 1.

[0023] Compared to the fully corrected values, the transparent type resulted in an average of 0.25D more myopia (error ±0.19D) as shown in P1 of Figure 5, and the filter type resulted in an average of 0.37D more myopia (error ±0.27D) as shown in P2 of Figure 5. In a survey asking which was easier to answer, 35.5% chose the transparent type and 64.5% chose the filter type.

[0024] Both the transparent and filter types produced results close to perfect correction. The filter type produced results that were slightly more myopic than the transparent type. In a questionnaire given to the subjects, many responded that it was easier to answer than the conventional red-green test, proving the usefulness of the test.

[0025] As described above, the red-green inspector 1 of the present embodiment 1 includes a window frame 7, and inside the window frame 7, a first prism 11 and a second prism 13 are arranged such that 11A and 13A face each other. As a result, the red-green tester 1 is provided separately from the optotype 33 and the light source 34, and the light transmitted through the first prism 11 and the second prism 13 can both be viewed by the subject's single eyeball 31. Therefore, the red-green tester 1 can improve the test accuracy of the red-green test.

[0026] According to this embodiment, in the red-green inspector 1, a thin green filter 15 is attached to the first prism 11, and a thin red filter 17 is attached to the second prism 13. As a result, the red-green inspector 1 allows the subject to simultaneously view the red light and the green light among the light transmitted through each of them, and therefore the red-green inspector 1 can perform a red-green inspection in which the subject simultaneously views the red light and the green light.

[0027] According to this embodiment, the red-green color inspector 1 includes a handle 5 . This allows the red-green test to be performed while the subject is holding the red-green tester 1. Therefore, the red-green tester 1 can be placed at any position depending on the positions of the optotype 33 and the eyeball 31 during the red-green test.

[0028] According to this embodiment, red-green inspector 1 has a first prism 11 for forming an image in the front of the subject's eye and a second prism 13 for forming an image in the back of the subject's eye, arranged with their bases facing each other within window frame 7. In a red-green inspection method using red-green inspector 1, window frame 7 is held in front of the subject's eyes, and one optotype is visually recognized simultaneously, and it is determined which of the optotypes seen through first prism 11 and second prism 13 is clearer. As a result, in the red-green test method using the red-green tester 1, the red-green tester 1 is provided separately from the optotype 33 and the light source 34, and the light transmitted through each of the first prism 11 and the second prism 13 can both be viewed by one eyeball 31 of the subject. This makes it easy to position or replace the optotype 33 according to the subject's visual acuity, thereby improving the test accuracy of the red-green test.

[0029] <Embodiment 2> (Configuration of an ophthalmic lens-type red-green tester) The second embodiment will be described below with reference to the drawings. FIG. 6 is a perspective view of an ophthalmoscope-type red-green tester 100 used in a red-green test. As shown in FIG. 6, red-green tester 100 has an annular window frame 107. Window frame 107 is provided with knob 105 that protrudes radially outward from window frame 107. Knob 105 is formed in a shape that can be held by a user with fingers or the like. In the second embodiment, a first prism 111 and a second prism 113 are fitted into window frame 107.

[0030] Fig. 7 is a cross-sectional view taken along plane VII of Fig. 6. Plane VII is a plane perpendicular to the radial direction of window frame 107 and each of bases 111A and 113A. 7, the first prism 111 and the second prism 113 are arranged in the window frame 107 so that their bases 111A and 113A face each other. The bases 111A and 113A are flat surfaces that stand in a direction perpendicular to the radial direction of the window frame 107. The longitudinal direction of the bases 111A and 113A extends along the radial direction of the window frame 107.

[0031] One end of bases 111A, 113A in a direction perpendicular to the radial direction of window frame 107 is located outside window frame 107. First prism 111 and second prism 113 have an inclined surface that is inclined at a predetermined angle toward window frame 107 as it extends from the end toward the circumferential direction of window frame 107. Therefore, first prism 111 and second prism 113 form a protruding shape with the end protruding from window frame 107.

[0032] A thin green filter 15 is attached to the first prism 111. A thin red filter 17 is attached to the second prism 113.

[0033] FIG. 8 is a front view showing the red-green tester 100 mounted on the eye examination frame 150. As shown in FIG. 8, the red-green tester 100 of the second embodiment is used in a state where it is attached to an optometry frame 150. The optometry frame 150 includes a pair of lens holders 152. The lens holders 152 are annular portions that detachably hold the red-green tester 100. One lens holder 152 is disposed in front of each of the left and right eyes 31 of the subject wearing the optometry frame 150. The knob 105 functions as a part to be grasped when attaching or detaching the red-green tester 100 to or from the optometry frame 150 .

[0034] A connecting portion 154 is provided between the two lens holding portions 152, connecting the two lens holding portions 152. On each of the two lens holding portions 152, on the opposite side to where the connecting portion 154 is connected, a temple portion 156 is provided to be hung on the ear of the subject.

[0035] 8, the red-green tester 100 is disposed so that the bases 111A and 113A each extend in the vertical direction when viewed from the front of the optometry frame 150. However, the red-green tester 100 is not limited to this, and the bases 111A and 113A of the red-green tester 100 may be disposed so that the bases 111A and 113A each extend in any direction when viewed from the front of the optometry frame 150.

[0036] When performing a red-green test using the red-green tester 100, the subject wears the eye examination frame 150 with the red-green tester 100 attached to one of the lens holding portions 152, and views the optotype 33 through the red-green tester 100. When red-green inspection is performed using red-green inspector 100, it is desirable that other lens holder 152 be provided with shield 158 that shields other eyeball 31 of the subject.

[0037] As described above, the red-green tester 100 according to the second embodiment is configured to be attachable to the optometry frame 150 and includes the knob 105. This allows the red-green test to be performed in the same way as other tests, while the red-green tester 100 is attached to the optometry frame 150. Therefore, the red-green test can be performed while the red-green tester 100 is positioned at a specified position from the eyeball 31, thereby improving the test accuracy of the red-green test.

[0038] <Third Embodiment> (Configuration of an alternating red-green detector) Hereinafter, the third embodiment will be described with reference to the drawings. Fig. 9 is a perspective view of an alternating-sight type red-green tester 200 used in red-green testing. As shown in Fig. 9, red-green tester 200 includes a handheld red-green tester main body 203, which includes a handle 205 and a window frame 207 fixed to the tip of handle 205. In the third embodiment, a thin green filter 15 and a thin red filter 17 are placed in window frame 207. The filters 15 and 17 are arranged side by side in a direction intersecting the direction in which the handle 205 extends in a plan view of the filters 15 and 17. The window frame 207 may be provided with a partition that separates the filter 15 and the filter 17 from each other.

[0039] (Red-green inspection method) Fig. 10 is a diagram showing a schematic diagram of a red-green inspection using a red-green inspector 200. In Fig. 10, the same parts as those in Fig. 3 are given the same reference numerals and their explanation will be omitted. Referring to FIG. 10, a red-green inspection method using red-green inspector 200 will be described. As shown in FIG. 10 , in a red-green test using the red-green tester 1, a corrective lens 32 is positioned in front of the eyeball 31, and a window frame 207 of this embodiment is positioned in front of the corrective lens 32. Filters 15 and 17 are placed in the window frame 207. The subject views one visual target 33 in front of the window frame 207 with either filter 15 or filter 17 placed in front of the corrective lens 32. In FIG. 3 , filter 15 is placed in front of the corrective lens 32.

[0040] As shown in FIG. 3, the light F emitted from the light source 34 is transmitted through the filter 15 and directed toward the eyeball, and the subject visually recognizes the green light. After this, the subject, with the filter 17 placed in front of the corrective lens 32, looks at one target 33 in front of the window frame 207. Of the light F emitted from the light source 34, red light that passes through the filter 17 heads toward the eyeball, and the subject looks at the red light. Then, an evaluation is made as to which of the visual target 33 through the green light and the visual target 33 through the red light is clearer. As a result, in a red-green test using the red-green tester 200, the target 33 is viewed alternately through the two filters 15 and 17, allowing red light and green light to be viewed using any target 33.

[0041] As described above, the red-green inspector 200 of the third embodiment includes a window frame 207, and within the window frame 207, there are disposed a filter 15 for forming an image in front of the subject's eye and a filter 17 for forming an image in front of the subject's eye. As a result, in a red-green test using the red-green tester 200, the optotype 33 can be viewed alternately through the two filters 15 and 17. Therefore, in a red-green test using the red-green tester 200, red light and green light can be viewed using any optotype 33.

[0042] The above-described embodiments and modifications merely represent one aspect of the present invention, and any modifications and applications are possible within the scope of the present invention.

[0043] In each of the above-described embodiments, the red-green inspector 1, 100, 200 includes a filter 15 for forming an image in front of the subject's eye, and a filter 17 for forming an image in front of the subject's eye. In addition, in the above-mentioned embodiments 1 and 2, the red-green inspection device 1, 100 is provided with a first prism 11, 111 for forming an image in front of the retina in the subject's eye, and a second prism 13, 113 for forming an image behind the retina in the subject's eye. However, the red-green testers 1, 100, and 200 may be configured so that the target 33 viewed through the filter 15 or the filter 17 is imaged either behind the retina or in front of the retina, depending on the condition of the eye being tested.

[0044] In the above-described embodiments, the red / green inspectors 1, 100, and 200 are provided with the filter 15 that is colored a predetermined color and the filter 17. However, this is not limiting, and the inspectors may be provided with a dichroic filter that transmits a predetermined color. Furthermore, for example, in the red-green detector 1, 100, the first prism 11 and the second prism 13 may be dichroic prisms that transmit predetermined colors. In this case, the red-green detector 1, 100 is formed without the filters 15 and 17.

[0045] For example, the red-green inspector 1, 100 includes the first prism 11 and the second prism 13, and the first prism 111 and the second prism 113, and has the inclined surfaces as described above. The inclination angles of the inclined surfaces of these prisms may be formed arbitrarily according to the distances L1 and L2.

[0046] For example, as shown in Figures 2 and 7, these prisms are formed in the shape of a right triangle when viewed in cross section at plane II or plane VII. However, this is not limiting, and these prisms may be formed in the shape of an isosceles triangle when viewed in cross section at plane II or plane VII. In this case, first prism 11 and second prism 13 have both ends of bases 11A and 13A protruding from both sides in the thickness direction of window frame 7. Similarly, first prism 111 and second prism 113 have both ends of bases 111A and 113A protruding from both sides in the thickness direction of window frame 107.

[0047] In the above-described embodiments, the first prism 11 and the second prism 13, the first prism 111 and the second prism 113, the filter 15, and the filter 17 are held by the window frames 7, 107, and 207. However, this is not limiting, and the first prisms 11 and 111, the second prisms 13 and 113, the filter 15, and the filter 17 can be applied to various types of optometric devices, as long as they are small. For example, they may be installed in various types of optometric devices or ophthalmic devices, such as a refractometer, a keratometer, a phoropter, or various types of visual acuity testing devices. Furthermore, for example, the red-green tester 1, 100, or 200 may be installed in these optometric devices or ophthalmic devices.

[0048] In the above-described embodiments, filter 15 is green and filter 17 is red. However, the present invention is not limited to this, and filter 15 and filter 17 may be any color as long as they are formed so that the difference in wavelength between the peak wavelength and the reference wavelength of filter 15 is approximately the same as the difference in wavelength between the peak wavelength and the reference wavelength of filter 17 within the visible light range.

[0049] Unless otherwise specified, the horizontal, vertical, and other directions, various numerical values, and shapes in the above-described embodiments include so-called equivalent ranges that provide the same effects as those directions, numerical values, and shapes. [Explanation of symbols]

[0050] 1, 100, 200 Red and green detector 3, 203 Red / Green Inspector Body 5, 205 Handle 7, 107, 207 Window frames 11, 111 First Prism 11A, 13A, 111A, 113A base 13, 113 Second Prism 13A Basis 15 Filter (first color filter) 17 Filter (Second Color Filter) 31 Eyeball 32 Corrective lenses 33, 33G, 33R optotypes 34 Light source 35 Retina 150 optometry frames 152 Lens holder 154 Connection part 156 Temple 158 Shield C, F light L1, L2 distance

Claims

1. A simultaneous vision type red-green detector, With window frames, A first prism and a second prism having different colors are disposed in the window frame so that their bases face each other. Red-green detector.

2. The first prism comprises: a first color for imaging in front of the subject's eye; The second prism comprises: a second color for imaging posteriorly within the subject's eye; 2. The red-green tester of claim 1.

3. The first color is green and the second color is red.

3. The red-green color inspector according to claim 2.

4. The window frame includes a handle.

4. The red-green color inspector according to claim 1.

5. The window frame includes a knob.

4. The red-green color inspector according to claim 1.

6. An alternating vision type red-green detector, With window frames, Within the window frame, a first color filter for forming an image in front of the subject's eye; a second color filter for imaging the subject's eye posteriorly; and is placed, Red-green detector.

7. a first prism for forming an image in the front of the subject's eye and a second prism for forming an image in the rear of the subject's eye are arranged in the window frame so that their bases face each other; The window frame is held in front of the subject's eyes, By visually recognizing one target, determining whether the visual target seen through the first prism or the visual target seen through the second prism is clearer; Red-green inspection method.

Images