Eye refractive power measurement apparatus and eye refractive power measurement method

Abstract

To provide an eye refractive power examination device capable of shortening the time required for measurement.SOLUTION: An eye-refractive-power examining device of the present disclosure includes a first optical system that is capable of generating a plurality of types of light having different characteristics and causes light to enter a subject eye that is one of both eyes of a subject, a sensor that detects retroillumination from the subject eye, and a determiner that determines a refractive power of the subject eye, in which the sensor detects an image formed by the retroillumination, and the determiner determines the refractive power of the subject eye based on a form of the image.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an eye refractive power testing apparatus and an eye refractive power testing method. [Background technology]

[0002] In conventional ophthalmological examinations, there is a technique called retinoscopy, in which the examiner shines a light on the retina while swinging it back and forth, and evaluates the eye's refraction from the relative movement of the light reflected from the retina. Utilizing this principle, a method has been proposed for objectively testing the eyesight of children, primarily by placing an illumination optical system and a beam splitter on a smartphone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2020 / 0046219 Summary of the Invention [Problem to be solved by the invention]

[0004] The eye refractive power testing device disclosed in Patent Document 1 can observe the movement of the retinal reflex of the subject's eye and determine whether the subject's eye is hyperopic, emmetropic, or myopic. However, determining the degree of hyperopia or myopia requires repeated measurements while successively changing the distance between the eye refractive power testing device and the subject's eye. This poses a problem in that it takes a long time to determine the refractive power of the subject's eye.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide an eye refractive power testing device that can shorten the time required for measurement. [Means for solving the problem]

[0006] The eye refractive power testing device disclosed herein is capable of generating multiple types of light with different characteristics and comprises a first optical system that directs light into the test eye, which is one of the test subject's eyes; a sensor that detects reflected light from the test eye; and a determiner that determines the refractive power of the test eye, wherein the sensor detects an image formed by the reflected light and the determiner determines the refractive power of the test eye based on the shape of the image.

[0007] The eye refraction testing device disclosed herein is capable of generating multiple types of light with different characteristics, and comprises a first optical system that causes light to be incident as a first light on one of the subject's eyes, which is the subject's eye to be tested; a second optical system that causes second light from a light source different from the first light to be incident on the other of the subject's eyes, which is the non-subject's eye; and a sensor that detects reflected light from the subject's eye due to the first light, wherein the sensor detects an image formed by the reflected light, and the second optical system controls the second light to change the state of the non-subject's eye.

[0008] The disclosed method for examining eye refractive power involves irradiating a test eye, which is one of the test subject's eyes, with light having controlled characteristics, and determining the refractive power of the test eye based on the shapes of multiple images formed by the reflected light of the test eye using multiple types of light with different characteristics.

[0009] The disclosed eye refractive power testing method involves irradiating a second light from a light source different from a first light incident on the test eye onto the non-test eye of the test subject, controlling the second light to change the state of the non-test eye, detecting reflected light caused by the first light, and determining the refractive power of the test eye. [Effects of the Invention]

[0010] According to the eye refraction testing device and eye refraction testing method disclosed herein, the refractive power of the test eye is measured based on the shape of the image formed by the reflected light, so that the refractive power can be easily determined by simply irradiating the test eye with light while maintaining a constant positional relationship between the test eye and the device, thereby reducing the time required for measurement. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating the structure of an eye refraction testing apparatus 100 according to a first embodiment. [Figure 2] 1 is a diagram showing an example of the configuration of an eye refraction testing apparatus 100 according to a first embodiment. [Figure 3] 2 is a diagram showing an example of a hardware configuration of a control device 50 included in the eye refraction measurement apparatus 100 according to the first embodiment. FIG. [Figure 4] 1 shows an example of an image formed on the sensor 40 by reflected light from the subject's eye 91a using the eye refraction measuring apparatus 100 according to the first embodiment. [Figure 5] 10 is a diagram showing an example of a comparison between an image formed on the sensor 40 by reflected light from the subject's eye 91a and the simulation result thereof. FIG. [Figure 6] 10 is a diagram showing an example of a comparison between an image formed on the sensor 40 by reflected light from the subject's eye 91a and the simulation result thereof. FIG. [Figure 7] 10A and 10B are diagrams illustrating the state of a subject's eye 91 when light is incident on the subject's eye 91. FIG. [Figure 8] 10A and 10B are diagrams illustrating the state of an eye 91 to be inspected when light subjected to different light flux controls is incident on the eye 91 to be inspected. [Figure 9] 10 is a schematic diagram illustrating the structure of a modified example of the eye refraction measuring apparatus 100 according to the first embodiment. FIG. [Figure 10] 1 is a diagram showing a control flow performed by the eye refraction measurement apparatus 100 according to the first embodiment to adjust the eye 91a to a position appropriate for the test. [Figure 11] FIG. 10 is a schematic diagram illustrating the structure of an eye refraction testing apparatus 100 according to a fourth embodiment. [Figure 12] 10 is a diagram showing an example of a comparison between an image formed on the sensor 40 by reflected light from the subject's eye 91a and the simulation result thereof. FIG. [Figure 13] 10 is a diagram showing an example of the relationship between the aspect ratio of an image 81 obtained by a sensor 40 and the refractive power of 91a. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of an eye refractive power testing device and an eye refractive power testing method according to the present disclosure will be described. Note that the forms of the drawings are merely examples and do not limit the present disclosure. Furthermore, parts with the same reference numerals in each drawing are the same or equivalent, and this is common throughout the entire specification. Furthermore, the size relationships between the components in the following drawings may differ from those in reality.

[0013] Embodiment 1 (Overall structure of eye refractive power testing device 100) 1 is a schematic diagram illustrating the structure of an eye refraction testing apparatus 100 according to the first embodiment. The eye refraction testing apparatus 100 includes a first optical system 10 for directing a first light 18 to an eye 91a to be tested, and a second optical system 20 for directing a second light 28, different from the first light 18, to an eye 91b not to be tested. The eye refraction testing apparatus 100 also includes a sensor 40 for detecting reflected light caused by the first light 18 that has been directed to the eye 91a to be tested. The eye refraction testing apparatus 100 directs light to the eye 91a to be tested by the first optical system 10, detects the reflected light from the eye 91a to be tested, and determines the refractive power of the eye 91a, whose refractive power is unknown, based on an image formed by the reflected light from the eye 91a to be tested. The first optical system 10, the second optical system 20, and the sensor 40 are supported by a support structure 30, and are configured so that their respective positional relationships can be maintained during testing of the subject's eye 91a. In addition, in the eye refraction testing apparatus 100 shown in Fig. 1, the sensor 40 and the display device 21, which functions as part of the second optical system 20, are mounted on a single mobile information terminal 60. The mobile information terminal 60 is, for example, a smartphone, and can control the sensor 40 and the display device 21 using installed application software to perform an eye refraction test using the eye refraction testing apparatus 100.

[0014] The sensor 40 detects reflected light from the subject's eye 91a and converts the image formed by the reflected light into data. The sensor 40 is, for example, an imaging device mounted on the portable information terminal 60, but may also be an independent imaging device 67. The sensor 40 may also be configured by combining an optical sensor and an optical element other than an imaging element, or by combining an imaging element with another optical sensor and an optical element.

[0015] (Configuration of the first optical system 10) As shown in FIG. 1 , first optical system 10 includes light source 11, lens 12, and reflecting mirror 13. Furthermore, first optical system 10 may include filter 14 between light source 11 and reflecting mirror 13. Light source 11 is mounted on light source unit 15. Lens 12 is also mounted on light source unit 15. However, lens 12 may be installed outside light source unit 15. Lens 12 is configured to be movable along the optical axis of light emitted from light source 11, and controls the luminous flux of light from light source 11.

[0016] 1, lens 12 is composed of a single convex lens, but it may be composed of multiple lenses and may further include other optical elements such as a filter. The configuration of lens 12 may be changed as appropriate as long as it can control the light flux required for eye refractive power testing.

[0017] The reflecting mirror 13 changes the path of the first light 18 emitted from the light source unit 15 so that it travels toward the subject's eye 91a. In FIG. 1, the light emitted from the light source unit 15 travels in the x1 direction, is reflected by the reflecting mirror 13, and its path is changed to travel in the z2 direction. Here, the direction in which the light emitted from the light source unit 15 travels may be referred to as the first direction, and the direction in which the light travels after being changed by the reflecting mirror 13 may be referred to as the second direction. In FIG. 1, the first direction and the second direction are orthogonal to each other, but the present invention is not limited thereto. The first direction and the second direction may intersect, and it is sufficient that the light is incident on the subject's eye 91a at least in the second direction.

[0018] 1, the reflecting mirror 13 is disposed on the optical axis between the subject's eye 91a and the sensor 40. The reflecting mirror 13 is preferably configured as a half mirror so that the sensor 40 can detect reflected light from the subject's eye 91a. This makes it possible for the eye refraction testing device 100 to arrange the light source 11, the reflecting mirror 13 (half mirror), the retina 92, and the sensor on the same axis.

[0019] The reflecting mirror 13 is not limited to a half mirror, and a beam splitter or polarization separation technology may be used. In other words, the reflecting mirror 13 may be replaced with another optical element or may be combined with another optical element as long as it changes the path of light from the light source 11 so that it can be introduced into the subject's eye 91a. These devices that change the path of light from the light source 11 so that it can be introduced into the subject's eye 91a may be collectively called an optical path separating means.

[0020] (Light source 11) The light source 11 projects light onto the subject's eye 91a, and the eye refraction testing device 100 determines the refraction by observing the image projected onto the retina 92. The light source 11 is formed of, for example, a filament or an LED, and forms a linear light source. When a filament is used as the light source 11, the light source 11 itself is linear, and therefore the image generated by this light source can be projected onto the retina 92 ​​to easily determine the refraction.

[0021] When the light source 11 is composed of an LED, it is preferable to combine a diffuser plate, a slit, etc. to form the light source 11 and form a line light source. In this case, it is possible to combine general-purpose parts to create the light source 11 of the desired shape, which also makes it possible to reduce costs.

[0022] The light source 11 may be a point light source. In this case, the light source 11 may be switchable between a line light source and a point light source. The light source 11 may also be in any shape, such as a cross or a star. By making the light source 11 a point light source, a cross or a star, it is effective not only for determining refractive power but also for detecting astigmatism.

[0023] (Configuration of the second optical system 20) 1, the second optical system 20 is configured to direct second light 28 to a non-test eye 91b, which is the other eye than the test eye 91a whose refractive power is to be tested, and to directly change the state of the non-test eye 91b by controlling the second light 28. The second optical system 20 sets the non-test eye 91b in a predetermined state, and utilizes the nature of the human body in which both eyes function in coordination to set the test eye 91a in a state suitable for testing refractive power.

[0024] The second optical system 20 includes a display device 21 having a screen that is visible to the non-examined eye 91b. A lens 22 is disposed between the display device 21 and the non-examined eye 91b and is configured to be movable in the direction of the optical axis.

[0025] The lens 22 is mainly used to sharpen or blur the visual target displayed on the display device 21. In FIG. 1, the lens 22 is configured as a single convex lens, but it may be combined with or replaced with other optical elements. Alternatively, the lens 22 may not be provided, and the non-subject's eye 91b may be configured to directly view the display device 21. In addition, the second optical system 20 may not include the display device 21 and the lens 22. The specific configuration of the second optical system 20 and the process of setting the non-subject's eye 91b to a predetermined state using the second optical system 20 will be described later.

[0026] (Configuration of support structure 30) 1, the support structure 30 supports the first optical system 10 and the second optical system 20 and maintains a predetermined positional relationship between the first optical system 10 and the second optical system 20 and the subject's eye 91a and the subject's eye 91b of the subject 90. The support structure 30 is also configured to hold an apparatus equipped with a sensor 40.

[0027] The support structure 30 maintains the positional relationship between the first optical system 10, the second optical system 20, and the sensor 40 and the subject's eye 91a and the non-subject's eye 91b in a state suitable for refractive power testing. That is, the subject's eye 91a is positioned so that the first light 18 is incident on it, and the subject's eye 91a is positioned on an extension line extending in the z direction from the sensor 40 through the reflecting mirror 13. If the sensor 40 is an imaging device, the subject's eye 91a should be positioned in the center of the angle of view that the imaging device can capture. The support structure 30 may be configured, for example, as head-mounted goggles, a face mount, or a scouter, to abut against the subject's head 90 and maintain the positional relationship between the first optical system 10, the second optical system 20, and the sensor 40 and the subject's eye 91a and the non-subject's eye 91b. Furthermore, the support structure 30 does not have to be attached to the head, as long as it has at least an abutment surface 31 against which the subject 90 presses their head.

[0028] (An example of the functional configuration of the eye refractive power testing apparatus 100) 2 is a diagram showing an example of the configuration of the eye refraction testing apparatus 100 according to the first embodiment. The eye refraction testing apparatus 100 causes light to be incident on the subject's eye 91a by the first optical system 10, detects reflected light from the subject's eye 91a by the sensor 40, and determines the refractive power of the subject's eye 91a based on an image formed by the reflected light from the subject's eye 91a. The eye refraction testing apparatus 100 includes a control unit 51, a determiner 52, an image acquisition unit 53, a storage unit 54, and an output unit 55, which may be used to test the refractive power of the subject's eye 91a.

[0029] The control unit 51 controls the first optical system 10 and the second optical system 20. The control unit 51 controls the operations of the light source 11, the lens 12, and the reflecting mirror 13, and causes the first light 18, controlled to a state appropriate for refractive power testing, to be incident on the subject's eye 91a. The image acquisition unit 53 acquires an image of the subject's eye 91a detected by the sensor 40 due to reflected light, and sends the data to the determiner 52. The image acquisition unit 53 also sends data of the image of the subject's eye 91a detected by the sensor 40 to the control unit 51 as needed. The control unit 51 controls the first optical system 10, the second optical system 20, the display device 21 (which may be included in the second optical system 20), and the sensor 40 (which may also include optical elements provided in the sensor 40) so that the state is appropriate for refractive power testing. The determiner 52 acquires the data acquired by the sensor 40 and the sample data stored in the memory unit 54, and determines the refractive power of the subject's eye 91a. The test result of the refractive power of the eye 91a to be examined determined by the determiner 52 is sent to the output unit 55. The output unit 55 causes the display device 21 to display the test result of the refractive power.

[0030] The control unit 51, the determiner 52, the image acquisition unit 53, the memory unit 54, and the output unit 55 may be included in a control device 50 that controls the entire eye refraction testing apparatus 100. Alternatively, the control unit 51, the determiner 52, the image acquisition unit 53, the memory unit 54, and the output unit 55 may be included in a portable information terminal 60 used as part of the eye refraction testing apparatus 100. In this case, the eye refraction testing apparatus 100 uses the portable information terminal 60 as the control device 50.

[0031] In the above, we have described a form in which the first optical system 10, the second optical system 20, the display device 21, and the sensor 40 are controlled by each functional block provided in the control device 50, but for example, the configuration may be such that some of the operations of the first optical system 10 and the second optical system 20 are manually operated by the user.

[0032] (Hardware configuration of the control device 50) 3 is a diagram showing an example of the hardware configuration of the control device 50 included in the eye refraction testing apparatus 100 according to Embodiment 1. The computer device applied to the control device 50 may be a single device or may be configured from a plurality of devices.

[0033] The CPU (Central Processing Unit) 61 executes various processes using computer programs and data stored in the storage device 62. In this way, the CPU 61 controls at least part of the operation of the eye refractive power measuring apparatus 100.

[0034] The storage device 62 is composed of, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and an external storage device. The storage device 62 stores setting data for the eye refractive power testing apparatus 100, computer programs and data related to the startup of the computer device used as the control device 50, computer programs and data related to the basic operation of the computer device, and the like.

[0035] The storage device 62 may include an external storage device such as a memory card, an optical disk such as a flexible disk (FD) or compact disk (CD) that can be attached to or detached from a computer device, a magnetic or optical card, an IC card, or a memory card.

[0036] The communication device 63 is a part that transmits and receives various data via a network, and any communication protocol, whether wired or wireless, may be used as long as communication between each information processing device can be performed. Furthermore, when the control device 50 is configured with multiple computer devices, the communication device 63 has a function for performing communication between the computer devices via the network. The communication device 63 transmits various data to other devices based on instructions from the CPU 61. Furthermore, the communication device 63 receives various data from other information processing devices and sends it to the control unit 51.

[0037] The input device 64 is a user interface such as a keyboard, mouse, or touch panel screen, which can be operated by the user to input various instructions to the CPU. The input device 64 also includes a microphone for voice input.

[0038] The output device 65 includes the display device 21, such as a liquid crystal screen or a touch panel screen, and displays the processing results of the CPU 61 as images, text, etc. The output device 65 also includes an audio playback device, such as a speaker, that outputs audio.

[0039] The CPU 61, the storage device 62, the communication device 63, the input device 64, and the output device 65 are all connected to a system bus. The CPU 61, the storage device 62, the communication device 63, the input device 64, and the output device 65 cooperate to realize the functions of each functional block of the control device 50.

[0040] (Regarding refractive power determination of the subject's eye 91a) FIG. 4 shows an example of an image formed on the sensor 40 by reflected light from the subject's eye 91a using the eye refraction testing apparatus 100 according to the first embodiment. In FIG. 4, the upper row shows numerical values ​​of refractive power, the middle row shows an image of reflected light captured by the sensor 40 when a divergent light beam is incident on the subject's eye 91a as the first light 18, and the lower row shows an image of reflected light captured by the sensor 40 when a convergent light beam is incident on the subject's eye 91a as the first light 18. The first light 18 is flux-controlled using the first optical system 10 to be a divergent light beam or a convergent light beam. In the example shown in FIG. 4, a model eye is used as the subject's eye 91a. The image of reflected light shown in FIG. 4 was captured by the sensor 40 after the refractive power of the model eye was adjusted within a range from −4 to +4, and a divergent light beam or a convergent light beam was incident on the subject's eye 91a as the first light 18 in each refractive power state. Note that when the refractive power is +, parallel light incident on the subject's eye 91a is focused behind the retina, meaning that the subject's eye 91a is in a hyperopic state. When the refractive power is -, parallel light incident on the subject's eye 91a is focused in front of the retina, meaning that the subject's eye 91a is in a myopic state. When the refractive power is ±0, parallel light incident on the subject's eye 91a is focused on the retina 92, meaning that the subject's eye 91a is in an emmetropic state.

[0041] Here, the divergent light beam refers to a light beam that enters the subject's eye 91a and widens as the light travels. The convergent light beam refers to a light beam that enters the subject's eye 91a and narrows as the light travels. The divergent light beam and convergent light beam that enter the subject's eye 91a are subjected to light beam control using the first optical system 10. Specifically, the light beam control is performed by refracting the light emitted from the light source 11 using a filter, changing the optical path length, or the like. The filter is an optical element such as a convex lens, a concave lens, a reflecting mirror, or a diffuser. The light beam that enters the subject's eye 91a refers to a light beam immediately before it strikes the surface of the cornea 93, and is a light beam that has not been refracted by each element of the subject's eye 91a.

[0042] As shown in the middle of FIG. 4 , when a diverging light beam is incident on the subject's eye 91a, an image 80 formed by reflected light from the subject's eye 91a can be observed, and this image can be obtained as an image by the sensor 40. The image 80 captured by the sensor 40 is composed of an image 81, which is the largest in the vertical direction, and smaller circular or elliptical images 82 and 83. However, there are images in which the images 81, 82, and 83 all overlap and are indistinguishable. Of the image 80, the image 81 is reflected light from the retina 92 ​​of the subject's eye 91a. The images 82 and 83 are reflected light from the cornea 93 or crystalline lens 94, which are located in front of the retina 92. The eye refraction testing apparatus 100 according to the first embodiment determines refractive power based on reflected light from the retina 92. In FIG. 4, the image with a refractive power of −4 is labeled with the symbol image 80, but in other images as well, the image that is longest in the vertical direction is image 81 formed by reflected light from the retina 92.

[0043] In the eye refraction measurement apparatus 100 according to the first embodiment, the sensor 40 detects an image formed by reflected light from the subject's eye 91a, and the refraction of the subject's eye 91a can be determined based on the state of the image. For example, if a diverging light beam is incident on the subject's eye 91a of an actual subject 90 and the shape of the image formed by reflected light in the image captured by the sensor 40 matches or resembles one of the images shown in the middle of FIG. 4, the refraction can be determined. Here, examples of the shape of the image used to determine the refraction include the image dimensions (length and width, tilt angle), image movement, image shape, image brightness, and image clarity. Image brightness may refer to the brightness of each image 81 (average brightness) or the brightness of each part of the image 81 (brightness distribution). The refraction may be determined by combining these image parameters or by using only some of the parameters.

[0044] As shown in the middle of Figure 4, when a predetermined divergent light beam is incident on the test eye 91a, the image 81 changes so that the horizontal dimension gradually decreases as the refractive power changes from -4 to -1, and changes so that the horizontal dimension gradually increases as the refractive power changes from -1 to +4.

[0045] Furthermore, as shown in the lower part of Figure 4, when a predetermined convergent light beam is incident on the test eye 91a, the horizontal dimension of the image 81 remains almost unchanged as the refractive power changes from -4 to -1, and the horizontal dimension gradually decreases as the refractive power changes from -1 to +4.

[0046] In the middle and bottom images of FIG. 4, the image 81 is relatively dark when the refractive power ranges from -4 to -1, and relatively bright when the refractive power ranges from -1 to +4.

[0047] As described above, by observing the size and brightness of the image 81 obtained by the sensor 40, the refractive power of the test eye 91a can be determined based on the type of light incident on the test eye 91a from the first optical system 10 and the obtained image 81.

[0048] (Determining refractive power using two types of light) Furthermore, if a divergent light beam and a convergent light beam are incident on the test eye 91a, the refractive power of which is unknown, as shown in Figure 4, and an image of the reflected light from each light beam is obtained, it becomes possible to more accurately determine the refractive power of the test eye 91a from the image 81 of these images.

[0049] When determining the refractive power of the subject's eye 91a using the eye refractive power testing device 100, it may be unclear which refractive power is indicated by the image due to retroillumination displayed in the image obtained by the sensor 40. For example, in the image obtained when a divergent light beam is incident as shown in the middle of Figure 4, the width of the central vertically elongated image is approximately the same in the image with a refractive power of -2 and the image with a refractive power of +1. Therefore, if an attempt is made to determine the refractive power by focusing on the size or shape of the image, it may not be possible to clearly determine whether the subject is hyperopic or myopic.

[0050] Therefore, in the eye refraction testing apparatus 100 according to the first embodiment, an image formed by retroillumination of the subject's eye 91a by a light beam subjected to different light beam controls is detected by the sensor 40. In the example of Fig. 4, the eye refraction testing apparatus 100 causes a convergent light beam to be incident on the subject's eye 91a, and an image formed by the resulting retroillumination is detected by the sensor 40. According to the images shown in the lower part of Fig. 4, the image for refractive power -2 and the image for refractive power +1 have significantly different widths. Therefore, even if the refractive power cannot be clearly determined from the retroillumination image by the divergent light beam, it is possible to accurately determine the refractive power based on the retroillumination image by the convergent light beam.

[0051] In other words, in the eye refractive power testing device 100 according to embodiment 1, the sensor 40 detects multiple images 80 formed by reflected light from the test eye 91a due to each of multiple types of light incident from the first optical system 10, and determines the refractive power of the test eye based on the multiple images 80.

[0052] In the example of Fig. 4, refractive power is determined using two types of light, a divergent light beam and a convergent light beam, but the eye refraction testing device 100 may use more types of light and determine refractive power using multiple images formed by their reflected light. Furthermore, the multiple types of light are not limited to a combination of a divergent light beam and a convergent light beam, but may be a combination of multiple types of divergent light beams or multiple types of convergent light beams. Furthermore, parallel light may be used as one of the multiple types of light.

[0053] (Regarding detection of retroreflection by sensor 40) 5 and 6 are diagrams showing an example of a comparison between an image formed on the sensor 40 by reflected light from the subject's eye 91a and the simulation results thereof. The eye refraction testing device 100 forms a line light source using a filament or LED as the light source 11, and irradiates the first light 18 so that the shape of the line light source is projected onto the retina 92 ​​of the subject's eye 91a. However, the image 81 projected onto the retina 92 ​​of the image formed by reflected light from the subject's eye 91a detected by the sensor 40 is captured via the cornea 93 and crystalline lens 94 of the subject's eye 91a, and therefore does not appear as is.

[0054] Furthermore, the reflected light from the test eye 91a is not only reflected light from the retina 92, but also reflected by each element of the test eye 91a through which the first light 18 passes, such as the surface of the cornea 93 and the surface of the crystalline lens 94, and is detected as reflected light. In the example shown in FIGS. 4 to 6, the image 81, which is the longest in the vertical direction, is an image due to reflected light from the retina 92, and the others are images due to reflected light from the surface of the cornea 93, the crystalline lens 94, etc. The images shown in FIGS. 4 to 6 are images of reflected light detected by the sensor 40 when a model eye is used as the test eye 91a and an examination is performed using the eye refraction testing device 100. The model eye has a structure equivalent to the retina 92, but because lenses are installed in place of the cornea 93 and the crystalline lens 94, images 82 and 83 due to reflected light from the lenses are captured in the image due to reflected light. However, in the eye refraction testing device 100, the refractive power is determined using the state of the image 81 due to reflected light from the retina 92, and therefore, even in a test using an eye model, the same results as when testing a human eyeball are obtained. Furthermore, although an actual eyeball has elements that refract light, such as the cornea 93 and the crystalline lens 94, these can be approximated as a single lens, and therefore the images shown in Figures 4 to 6 are substantially the same as those obtained when testing a human eyeball.

[0055] (Example 1 of refractive power determination using the image 81 generated by the backlighting detected by the sensor 40) The eye refraction testing device 100 determines the refractive power by utilizing the state of the image 81 formed by reflected light from the retina 92 ​​in the image captured by the sensor 40. As an example, the eye refraction testing device 100 determines the refractive power by utilizing the aspect ratio of the dimensions of the image 81 that is the longest vertically among the captured images.

[0056] The images shown in FIGS. 4 to 6 (the images shown in the lower rows in FIGS. 5 and 6) were produced using the eye refraction measuring device 100, with a linear light source used as the light source 11. As an example, an image 81 is captured by irradiating the subject's eye 91a with the first light 18 in the vertical direction of the subject's eye 91a (the y direction in FIGS. 4 to 6). At this time, the vertical dimension of the subject's eye 91a of the image 81 depends on the size of the pupil because the light beam is partially blocked by the pupil (because a light beam larger than the pupil diameter is irradiated toward the pupil, the light beam that protrudes beyond the pupil is blocked). However, the dimension in the width direction (x direction in FIGS. 4 to 6) may appear enlarged or similar in width to the linear light source depending on the refractive power of the subject's eye 91a (the refractive power of the cornea 93 and the crystalline lens 94 in the case of a human eyeball, or the refractive power of lenses corresponding to the cornea 93 and the crystalline lens 94 in the case of a model eye). That is, the width of the image 81 varies depending on the refractive power of the subject's eye 91 a. The eye refractive power testing device 100 utilizes this characteristic to prepare a sample of the image 81 in advance according to the refractive power of the subject's eye 91 a, and compares the sample with an image obtained by actually performing the test to determine the refractive power.

[0057] The refractive power is determined by comparing the shape of the image 81 obtained by actually performing the test with that of a specimen. As an example, the aspect ratio of the dimensions of the image 81 is calculated as a numerical value, and compared with the numerical value of the aspect ratio of the dimensions of the image 81 in the specimen, and the power (diopter) of the specimen with the closest numerical value is determined as the power of the eye 91a to be examined. Although images in which the power is varied in increments of 1 are shown in Figs. 4 to 6, the eye refractive power testing device 100 may have specimens with even finer powers.

[0058] Furthermore, when a light beam larger than the pupil diameter is irradiated onto the subject's eye 91a as the first light 18, the aspect ratio of the image 81 may depend on the pupil diameter, so an image 81 corresponding to the pupil diameter of the subject's eye 91a may be provided as a specimen. Since the pupil diameter of the subject's eye 91a can also be confirmed from the images shown in Figures 4 to 6, the eye refraction testing apparatus 100 may determine the pupil diameter of the subject's eye 91a from the image obtained by the sensor 40, and compare the specimen corresponding to that pupil diameter with the image 81 obtained in the test.

[0059] Although the above description deals with the case where the first light 18 or the reflected light is partially blocked by the pupil, the first light 18 may have a vertical length smaller than the pupil diameter so that the light beam is not blocked by the pupil. In this case, the eye refraction testing device 100 can compare the specimen with the image 81 obtained by the test and determine the refractive power independently of the pupil diameter, so it does not need to have specimens for each pupil diameter.

[0060] Furthermore, the above-described eye refraction testing apparatus 100 is used to perform the test with the linear light source oriented vertically relative to the subject's eye 91a. However, the linear light source may be oriented (longitudinal) in the width direction of the subject's eye 91a (the x-direction in FIGS. 4 to 6), or may be tilted relative to both the vertical and width directions. For example, the linear light source may be incident on the subject's eye 91a with its longitudinal direction tilted by a predetermined angle relative to the vertical direction of the subject's eye 91a. The sensor 40 acquires images 81 obtained by tilting the linear light source by a predetermined angle. The eye refraction testing apparatus 100 can determine not only the refractive power of the subject's eye 91a but also whether the subject's eye 91a has astigmatism by comparing the shapes of multiple images 81 acquired at each tilt angle of the linear light source. The eye refraction testing apparatus 100 may be provided with a sample of images 81 corresponding to the astigmatism axis direction and astigmatism power, and determine astigmatism by comparing the sample with an image acquired by actually performing the test.

[0061] The eye refraction testing device 100 may also determine refractive power and detect astigmatism by changing the shape of the light source 11. For example, if the light source 11 is a point light source, the image 81 will be round if normal, but if the subject's eye 91a has astigmatism, the image 81 acquired by the sensor 41 will be partially distorted. This allows the presence or absence of astigmatism in the subject's eye 91a to be detected. The light source 11 may also be shaped as a combination of linear light sources, such as a cross or star, arranged radially from the center. In this case, the eye refraction testing device 100 may also be provided with a sample of the image 81 corresponding to the axis direction and degree of astigmatism in advance, and may determine astigmatism by comparing the sample with an image obtained by actually performing the test.

[0062] (Example 2 of refractive power determination using the image 81 generated by the backlighting detected by the sensor 40) FIG. 12 is a diagram showing an example of a comparison between an image formed on the sensor 40 by reflected light from the subject's eye 91a and the results of a simulation of the image. In FIG. 12, a model eye is used as the subject's eye 91a, and parallel light is incident as the first light 18, and the eye is examined using the eye refraction testing device 100. The upper part shows image data acquired by the sensor 40, and an image 81 is shown. This image data is free from the influence of reflected light from elements other than the retina 92 ​​(the influence is negligibly small). The lower part shows an image obtained by simulation under the same conditions as those under which the image data in the upper part was obtained.

[0063] An example of the relationship between the shape of the image 81 obtained by the sensor 40 and the refractive power of the subject's eye 91a will be described using the example of Fig. 12. When a light beam from a line light source is incident on the subject's eye 91a, the aspect ratio (the ratio of the dimensions indicated by "vertical width" and "horizontal width" in Fig. 12) of the image 81 detected by the sensor 40 changes depending on the refractive power of the subject's eye 91a. The refractive power of the subject's eye 91a can also be determined from the value of this aspect ratio.

[0064] Fig. 13 is a diagram showing an example of the relationship between the aspect ratio of an image 81 obtained by the sensor 40 and the refractive power of the image 81a. Fig. 13 shows the change in the aspect ratio of the image 81 when the first light 18 having the same characteristics is incident on the subject's eye 91a and the refractive power of the subject's eye 91a is changed. The data in Fig. 13 are the results of measurements when the pupil diameter of the subject's eye 91a is 1.5, 2.0, 2.5, 3.0, and 3.5 mm.

[0065] The aspect ratio value of the image 81 is expressed as (width) / (height) [%]. This value gradually decreased as the refractive power went from 4D to 2D, and tended to increase as the refractive power went from 2D to -4D. The tendency of the change in the aspect ratio value was the same regardless of the pupil diameter of the test eye 91a, but the rate of change varied depending on the pupil diameter. The rate of change in the aspect ratio value tended to be greater as the pupil diameter became smaller from 4D to 2D. The rate of change in the aspect ratio value tended to be greater as the pupil diameter became larger from 2D to -4D.

[0066] 13 shows an example in which parallel light is incident on the subject's eye 91a as the first light 18, an image 81 formed on the retina 92 ​​is detected by the sensor 40, and the aspect ratio of the image 81 is measured. When the same parallel light is used for the test, the aspect ratio of the image 81 varies depending on the size of the pupil diameter, but the tendency of change is consistent even when the pupil diameter increases, and it has been found that the eye refraction testing device 100 can determine the refractive power using the shape of the image 81 of reflected light from the retina 92, particularly the aspect ratio.

[0067] 12, the image 81 obtained by the sensor 40 is obtained as a blurred image or a clear image depending on the refractive power of the subject's eye 91a. When determining the refractive power of the subject's eye 91a based on the shape of the image 81, the determination can be made based on the value of the aspect ratio of the image 81 as described above, or, for example, the definition and brightness distribution of the image 81 can be used as criteria.

[0068] Furthermore, in determining the refractive power of the subject's eye 91a using the eye refraction testing apparatus 100, the divergent light beam and the convergent light beam shown in Example 1 and the parallel light beam shown in Example 2 may be used in combination for the test, or each may be used alone for the test. Furthermore, the images shown in the examples are measured based on an example of the first optical system 10 such as the light source 11, and do not limit the determination of the eye refraction power using the eye refraction testing apparatus 100 of the present disclosure.

[0069] The simulation results shown in the lower part of Fig. 12 are reproductions of an image 81 that can be observed by the sensor 40 when parallel light is incident as the first light 18 on the subject's eye 91a under the same conditions as the measurement results shown in the upper part of Fig. 12. The measurement results in Fig. 12 can also be reproduced by simulating light rays, and the image 81 obtained by the sensor 40 can be predicted by simulation even if the light flux generated by the first optical system 10 and the pupil diameter are changed. Therefore, it is also possible to create a specimen to be used in the eye refraction testing apparatus 100 from the simulation results.

[0070] (Simulation results of the image 80 of the reflected light from the test eye 91a) The upper diagrams of Figures 5 and 6 show simulation results for images formed on the cornea by retroillumination from the subject's eye 91a. In contrast, the images shown in the lower diagrams of Figures 5 and 6 are images of retroillumination detected by the sensor 40. Therefore, the simulation results do not necessarily match the images in the lower diagrams, but the tendency of change in width of image 84 relative to power (diopter) of image 84 shown in the simulation results matches the tendency of change in width of image 81 due to retroillumination shown in the actually measured images.

[0071] 5 shows a case where a diverging light beam is irradiated onto the subject's eye 91a, and in the image 84 of the simulation result, the width of the image 84 gradually narrows as the power increases from -3D to -1D, and gradually widens as the power increases from -1D to +3D. In contrast, in the image 81 of the actual measurement result, the width of the image 81 gradually narrows as the power increases from -3D to -1D, and gradually widens as the power increases from -1D to +3D. As such, although the absolute values ​​of the widths of the image 84 of the simulation result and the image 81 of the actual measurement result do not match, the trends of change are consistent, and therefore it can be seen that the refractive power of the subject's eye 91a can be determined using the image 81 of the actual measurement result.

[0072] 6 shows a case where a convergent light beam is irradiated onto the subject's eye 91a, and the width of the image 84 obtained as a result of the simulation gradually narrows as the power increases from -3D to +3D. In contrast, the width of the image 81 obtained as a result of the actual measurement also gradually narrows as the power increases from -3D to +3D.

[0073] As described above, although the absolute width values ​​of the image 84 of the simulation result and the image 81 of the actual measurement result do not match, the trends in the width changes are the same, and therefore it can be seen that the refractive power of the test eye 91a can be determined using the image 81 of the actual measurement result.

[0074] (Principle of determining refractive power of the subject's eye 91a) 7 is a diagram illustrating the state of the subject's eye 91 when light is incident on the subject's eye 91. With reference to FIG. 7, a description will be given of how refractive power is determined using an image formed on a retina 92 ​​when light is incident on the subject's eye 91.

[0075] FIG. 7A shows the case where the subject's eye 91 is hyperopic, FIG. 7B shows the case where the subject's eye 91 is emmetropic, and FIG. 7C shows the case where the subject's eye 91 is myopic. For the sake of explanation, FIGS. 7A to 7C illustrate the states of hyperopia, emmetropia, and myopia by changing the axial length of the subject's eye 91 (the length from the left to right of the center of the subject's eye 91 in FIG. 7). However, in reality, hyperopia, emmetropia, and myopia are caused not only by the axial length but also by differences in the refractive power (or ability to adjust refractive power) of the cornea 93, the crystalline lens 94, etc. In FIGS. 7A to 7C, the refractive power of the cornea 93, the crystalline lens 94, etc. is assumed to be constant, and light entering the subject's eye 91 is assumed to be refracted only by the crystalline lens 94.

[0076] As shown in Fig. 7B, when the subject's eye 91 is in a state of emmetropia, the incident parallel light is focused on the retina 92. As shown in Fig. 7A, when the subject's eye 91 is in a state of hyperopia, the incident light is focused behind the retina 92. As shown in Fig. 7C, when the subject's eye 91 is in a state of myopia, the incident light is focused in front of the retina 92.

[0077] That is, when the subject's eye 91 is in a hyperopic or myopic state, the image projected onto the retina 92 ​​is blurred. For example, when a point light source at substantially infinity is viewed in the emmetropic state shown in Fig. 7B, an image b of the point light source is projected onto the retina 92. However, in the hyperopic state shown in Fig. 7A, the point light source is projected onto the retina 92 ​​as a blurred circular image a, and even in the myopic state shown in Fig. 7C, the point light source is projected onto the retina 92 ​​as a blurred circular image c.

[0078] Therefore, if light is incident on the subject's eye 91 and the image formed on the retina 92 ​​can be observed by capturing an image with the sensor 40, it is possible to determine whether the subject is hyperopic, emmetropic, or myopic, and the degree of hyperopia or myopia can also be determined based on the degree of blurring of the image. The eye refraction testing apparatus 100 according to the first embodiment utilizes this principle to determine the refractive power of the subject's eye based on the image 80 formed by the reflected light detected by the sensor 40.

[0079] However, as can be seen from the blurred image a shown in FIG. 7A and the blurred image b shown in FIG. 7C, when the subject's eye 91 is in a state of hyperopia or myopia, the degree of blur may be the same, as in the images a and c projected onto the retina 92. In this case, it may not be possible to clearly determine whether the subject's eye is in a state of hyperopia or myopia based solely on the shape of the images a and c projected onto the retina 92. Therefore, in the eye refraction testing apparatus 100 according to the first embodiment, light beams subjected to two types of light flux control are incident on the subject's eye 91, and the refractive power is determined based on the images projected onto the retina 92 ​​by the respective light beams. Next, a case where light beams subjected to different light flux control are incident on the subject's eye 91 will be described.

[0080] 8A to 8C are diagrams illustrating the state of the subject's eye 91 when light with different light flux controls is incident on the subject's eye 91. FIG. 8A shows the case where the subject's eye 91 is hyperopic, FIG. 8B shows the case where the subject's eye 91 is emmetropic, and FIG. 8C shows the case where the subject's eye 91 is myopic. In addition, among the lines extending from left to right in the diagram and entering the subject's eye 91, the solid lines indicate parallel light beams, the dashed lines indicate convergent light beams, and the dashed-dotted lines indicate divergent light beams. Each line indicates the light beam with the greatest range (farthest from the optical axis) among the light beams passing through the pupil 95.

[0081] 8A and 8C, the images a1 and c1 formed on the retina 92 ​​by the parallel beam of light are approximately the same size, but when compared with the images a2 and c2 formed on the retina 92 ​​by the convergent beam of light (dashed line), it is found that their sizes are significantly different. In other words, while it was not possible to clearly determine whether the patient is hyperopic or myopic by comparing only the shapes of the images a1 and c1 formed on the retina 92 ​​by the parallel beam of light, it is now possible to clearly determine whether the patient is hyperopic or myopic by comparing the shapes of the images a2 and c2 formed by the convergent beam of light.

[0082] Although Figure 8 shows one example each of a divergent light beam, a parallel light beam, and a convergent light beam, it is also possible to make the refractive power determination easier by preparing multiple light beams with different degrees of divergence or convergence and irradiating two or more different types of light beam-controlled light into the test eye 91.

[0083] Furthermore, in the eye refraction testing device 100 according to the first embodiment, the refractive power is determined by objectively observing the image formed on the retina 92 ​​with the sensor 40. Therefore, the retroillumination detected by the sensor 40 is light that is reflected by the retina 92 ​​and refracted after passing through the lens 94, cornea 93, etc. Therefore, the image that can be objectively observed by the sensor 40 is not the exact image formed on the retina 92. However, by observing the image 80 formed by the retroillumination that has passed through the lens 94, cornea 93, etc., it is possible to detect differences in the images formed on the retina 92, and therefore the refractive power can be determined from the image 80 formed by the retroillumination detected by the sensor 40.

[0084] The eye refraction testing device 100 may store in advance samples of images formed by retroillumination of eyes in hyperopic, emmetropic, or myopic states. These samples may be, for example, samples in which the refractive power of an eye has been accurately measured in advance using another device and the retroillumination image is associated with the refractive power. Alternatively, the sample may be a retroillumination image of a model eye, or a retroillumination image obtained by optical simulation. The eye refraction testing device 100 may compare the sample with an image formed by retroillumination of the test eye 91a whose refractive power is to be determined, and determine the level of refractive power. In other words, the eye refraction testing device 100 stores, as samples, images formed by retroillumination captured using a model eye or a human eye whose degree of hyperopia or myopia is known, in a database associated with the refractive power. The eye refractive power measuring device 100 obtains and analyzes a retroilluminated image of the subject's eye 91a to be measured, and determines the refractive power by comparing the image with a database.

[0085] The sample data and database described above do not have to be stored in a storage device included in the eye refraction testing apparatus 100, and may be made accessible via a network, for example.

[0086] As described above, by using the eye refraction testing device 100 according to embodiment 1, an eye refraction testing method can be performed in which light with controlled light flux is incident on the test eye 91a, which is one of the eyes of the subject 90, and the refractive power of the test eye 91a is determined based on the shape of the image formed by reflected light from the test eye 91a.

[0087] In addition, the eye refractive power testing method may involve irradiating multiple types of light onto the test eye 91a and determining the refractive power of the test eye 91a based on the shapes of multiple images formed by the reflected light of the test eye 91a caused by the multiple types of light.

[0088] The eye refractive power testing method may also be a method of comparing a plurality of images formed by reflected light from the subject's eye 91a with a sample stored in advance to determine the refractive power of the subject's eye 91a.

[0089] (Regarding control of the subject eye 91a using the non-subject eye 91b) As shown in FIG. 1 , the eye refraction measuring apparatus 100 according to the first embodiment determines the refractive power of an eye 91a to be measured by irradiating the first light 18 from the first optical system 10 onto the eye 91a. However, determining the refractive power requires that the refractive power of the crystalline lens 94 of the eye 91a be set to a predetermined state. Generally, when measuring the refractive power of the eye 91a, the crystalline lens 94 is set to a relaxed state to allow the accommodative power of the crystalline lens 94 to be relaxed. In this relaxed state, the crystalline lens 94 is at its thinnest. The crystalline lens 94 focuses on the retina 92 ​​by using the ciliary muscle to thicken the crystalline lens 94 to increase its refractive power or to thin it to decrease its refractive power. Relaxing the ciliary muscle allows the crystalline lens 94 to be at its thinnest state.

[0090] In the eye refraction measuring apparatus 100 according to the first embodiment, the second light 28 from the second optical system 20, which is different from the first light 18 from the first optical system 10, is incident on the non-test eye 91b, which is not the test eye 91a, of the subject 90. The second light 28 from the second optical system 20 is incident on the non-test eye 91b of the subject 90, and by controlling the second light 28 to change the state of the non-test eye 91b, the state of the test eye 91a is controlled to be suitable for refractive power determination. This is because both eyes of a human body normally have the property of adjusting in coordination, and when the ciliary muscle of the non-test eye 91b relaxes and the crystalline lens 94b thins, the ciliary muscle of the test eye 91a also relaxes at the same time and the crystalline lens 94a thins.

[0091] The eye refraction testing device 100 according to embodiment 1 utilizes the property that both eyes of the human body work in coordination, and controls the state of the test eye 91a by irradiating the second light 28 to the non-test eye 91b and changing the state of the non-test eye 91b.

[0092] (Example 1 of the second light 28 incident on the non-examined eye 91b) 1, the eye refraction testing device 100, for example, displays an image on a display device 21, and causes light emitted from the display device 21 to be incident on a non-examined eye 91b as a second light 28. A lens 22 is disposed between the display device 21 and the non-examined eye 91b, and is configured to be movable in both directions along the optical axis direction of the second light 28.

[0093] The lens 22 can blur or sharpen the image seen by the non-tested eye 91b by moving it in the optical axis direction of the second light 28. By moving the lens 22 in front of the non-tested eye 91b to change the image seen by the non-tested eye 91b from a clear state to a blurred state, the refractive power of the non-tested eye 91b is adjusted to a relaxed state. The eye refraction testing device 100 can also control the test eye 91a to a relaxed state by controlling the lens 22. This method is also called the fogging method. The lens 22 can be replaced with another optical element that achieves a similar effect.

[0094] (Example 2 of the second light 28 incident on the non-examined eye 91b) 1, the accommodative power of the non-subject's eye 91b can also be relaxed by darkening the image displayed on the display device 21. Specifically, one method is to have the non-subject's eye 91b look at an image including a star or the like displayed on the display device 21, and then suddenly darken the image. Alternatively, the eye refraction testing device 100 may be configured such that another optical element is arranged in place of or in series with the lens 22, so as to block light entering the non-subject's eye 91b.

[0095] (Example 3 of the second light 28 incident on the non-examined eye 91b) 9 is a schematic diagram illustrating the structure of a modified example of the eye refraction testing apparatus 100 according to Embodiment 1. In this modified example, the eye refraction testing apparatus 100 is not provided with the display device 21, and is configured so that the non-tested eye 91b can view a distant target. That is, in this modified example, the surrounding environment in which the eye refraction testing apparatus 100 is used is utilized to show the non-tested eye 91b a distant target (such as an eye chart posted on the wall or a distant view), thereby relaxing the accommodative power of the non-tested eye 91b.

[0096] 1 may be configured to be detachable from the support structure 30, and the mobile information terminal 60 equipped with the sensor 40, which is an imaging device, and the display device 21 may be replaced with another device. In the modified example shown in FIG. 9, an imaging device 67 is attached to the support structure 30 instead of the mobile information terminal 60, and the view in front of the non-examined eye 91b is not obstructed, making it possible to use a visual target in the surrounding environment as the second optical system 20.

[0097] (Control of the proper position of the subject's eye 91a by controlling the second light 28) 10 is a diagram showing a control flow performed by the eye refraction testing apparatus 100 according to Embodiment 1 to adjust the subject's eye 91a to a position appropriate for testing. The eye refraction testing apparatus 100 may perform control to guide the subject's eye 91a to a position appropriate for the refraction test. Specifically, as described above, the subject's eye 91a is adjusted to a position appropriate for testing by moving the non-subject's eye 91b using the second light 28.

[0098] When adjusting the subject's eye 91a, the eye refraction testing apparatus 100 first acquires image data from the sensor 40 (step S1) and checks the positional relationship between the first light 18 and the subject's eye 91a. The first light 18 is controlled by the first optical system 10 and irradiated at a fixed position. However, the position of the subject's eye 91a may be shifted from the position of the first light 18 due to factors such as a misalignment between the subject 90 and the eye refraction testing apparatus 100 or the orientation of the subject's eye 91a. The eye refraction testing apparatus 100 first checks whether or not the image 81 reflected by the retina 92 ​​is present in the image data (step S2). If the image data does not contain the image 81 (No in step S2), the subject's eye 91a or the first optical system 10 may be controlled so that the image 81 reflected by the retina 92 ​​can be confirmed in the image data (step S3). If the image 81 is confirmed in the image data (Yes in step S2), the eye refraction testing device 100 compares the position of the center of the image of the reflected light by the first light 18 (for example, the image 81 shown in FIG. 4) with the position of the center of the pupil in the image acquired from the sensor 40, and measures the amount of deviation. The amount of deviation may be expressed, for example, by the number of pixels or dimensions of the image.

[0099] Next, the eye refraction testing apparatus 100 determines whether the amount of deviation is equal to or greater than a reference value (step S4). If the amount of deviation is equal to or greater than a predetermined value (Yes in step S4), the eye refraction testing apparatus 100 controls, for example, the state of the second light 28 so as to reduce the amount of deviation (step S5). For example, when moving the non-tested eye 91b using a visual target displayed on the display device 21, the position of the visual target on the screen of the display device 21 is moved in a direction that reduces the amount of deviation between the pupil and the image 81. The amount of movement of the visual target is adjusted appropriately depending on the amount of deviation. The eye refraction testing apparatus 100 may also instruct the test subject 90 by audio guidance to move the test eye 91a in a direction that reduces the amount of deviation.

[0100] After step S3 or step S5 is performed, or in parallel with step S3 or step S5, the eye refraction testing apparatus 100 acquires image data from the sensor 40 again (return to step S1).

[0101] When the amount of deviation becomes equal to or less than a predetermined value (No in step S4) after the above control is performed, the control ends and the eye refractive power test is performed.

[0102] Note that steps S1 to S5 may be performed in parallel. For example, while controlling the movement of the optotype displayed on the display device 21, the image data may be checked to determine whether the image 81 is displayed in the image data and whether the amount of deviation is within an appropriate range. When the amount of deviation is within the appropriate range, for example, the display device 21 may display a message that the subject's eye 91a is in an appropriate state for the examination, or the subject 90 may be notified by voice.

[0103] As described above, by using the eye refraction testing apparatus 100 according to embodiment 1, it is possible to implement an eye refraction testing method in which second light 28, which is different from the first light 18 incident on the test eye 91a, is incident on the non-test eye 91b of the subject 90, which is not the test eye 91a, and the second light 28 is controlled to change the state of the non-test eye 91b, and the reflected light caused by the first light 18 is detected to determine the refractive power of the test eye 91a.

[0104] Note that the second light 28, which is different from the first light 18 incident on the subject's eye 91a, may be incident on the non-subject's eye 91b and used for purposes other than refractive power determination. For example, when photographing the subject's eye 91a after controlling the state of the subject's eye 91a to a predetermined state, the control using the non-subject's eye 91b with the second light 28 may be applied to any action on the subject's eye 91a.

[0105] Furthermore, the eye refraction testing method described in the first embodiment may be performed using a device or instrument with a different configuration, rather than using the eye refraction testing device 100 described above.

[0106] Embodiment 2 In the second embodiment, an eye refraction determination will be described which is different from the eye refraction determination performed by the eye refraction testing apparatus 100 according to the first embodiment. The eye refraction testing apparatus 100 according to the second embodiment can determine the refraction of the subject's eye 91a by a technique called retinoscopy, and can also determine the refraction by combining the refraction determination according to the first embodiment with retinoscopy.

[0107] Retinoscopy is a method of determining refractive power using a retinoscope. A retinoscope is an instrument that projects a thin beam of light onto the eye and observes the resulting retro-illumination (light reflected within the eye). The retinoscope is moved back and forth and side to side while projecting the light. Ophthalmologists use the retinoscope to observe the movement and pattern of the retro-illumination of the subject's eye 91a to determine the refraction state. Specifically, while observing the retro-illumination, ophthalmologists place test lenses of various diopters in front of the subject's eye 91a, find a test lens with a diopter that stops (neutralizes) the movement of the retro-illumination, and determine the diopter of the subject's eye 91a. Note that retinoscopy also requires the subject's eye 91a to be in a relaxed state of accommodation.

[0108] Conventional retinoscopy is performed using a retinoscope and test lens, but because a doctor or other medical professional operates the retinoscope and determines refractive power by observing the movement of the observed retroillumination, accuracy may not be stable unless the doctor or other medical professional is technically skilled.

[0109] (Retinoscopy using eye refractive power testing device 100) 1 can maintain a predetermined distance between the subject's eye 91a and the first optical system 10 and the sensor 40. Specifically, the head of the subject 90 is brought into contact with the contact surface 31, which is the front surface of the support structure 30, and the positional relationship between the eye refraction testing device 100 and the subject's eye 91a can be maintained constant. This makes it possible to maintain a constant distance between the first optical system 10 and the subject's eye 91a and a constant distance between the sensor 40 and the subject's eye 91a.

[0110] The first optical system 10 includes a reflecting mirror 13 that changes the light emitted from the light source 11 in the x1 direction to the y2 direction. The reflecting mirror 13 has a rotation axis 13a, and can rotate a mirror 13b around the rotation axis 13a. The reflecting mirror 13 can control the angle of the first light 18 emitted in the y2 direction by changing the angle of the mirror 13b. The first optical system 10 can change the angle of the mirror 13b and change the angle of the first light 18 emitted from the mirror 13b toward the subject's eye 91a, thereby moving the image formed on the retina 92 ​​by the first light 18.

[0111] 1, reflecting mirror 13 is configured to change the angle of mirror 13b within the xy plane, but it may also be configured to have a rotation axis other than rotation axis 13a so that the image reflected on retina 92 ​​can be moved not only in the x direction but also in the z direction perpendicular to the xy directions. Also, reflecting mirror 13 may be configured to combine multiple rotation axes so that the image reflected on retina 92 ​​can be moved in any direction.

[0112] The sensor 40 detects an image formed by the reflected light from the subject's eye 91a. The image formed by the reflected light is captured by the sensor 40 as an image 80 as shown in Fig. 2, and by moving the reflecting mirror 13, the movement of the reflected light from the retina 92 ​​can also be detected.

[0113] With a test lens sandwiched between the sensor 40 and the subject's eye 91a, the eye refraction testing apparatus 100 detects when the reflected light from the retina 92 ​​obtained by the sensor 40 is synchronous (the direction in which the light is moved under control of the first optical system 10 matches the direction of the movement of the reflected light), when the reflected light from the retina 92 ​​obtained by the sensor 40 is retrograde (the direction in which the light is moved under control of the first optical system 10 is opposite to the direction in which the reflected light moves), or when the reflected light from the retina 92 ​​obtained by the sensor 40 is neutralized (when there is no movement of the reflected light even when the light is moved under control of the first optical system 10). If the above neutralization can be detected when a certain test lens is used, the eye refraction testing apparatus 100 can determine the refractive power of the subject's eye 91a based on the test lens.

[0114] It should be noted that the refractive power of the eye 91a to be examined may be determined based on the state (focal length) of the lens mechanism provided in the imaging device used as the sensor 40, for example, without using the test lens described above.

[0115] As described above, by controlling the first optical system 10 to move the first light 18 and observing the movement of the reflected light from the retina 92, the eye refraction testing device 100 can determine whether the test eye 91a is hyperopic, emmetropic, or myopic.

[0116] If the eye refraction measurement apparatus 100 can determine whether the subject's eye 91a is hyperopic, emmetropic, or myopic, it can determine the refractive power without observing multiple images 80 formed by the retroillumination of the first light 18 that has been subjected to multiple types of light flux control as described in the first embodiment. In other words, the eye refraction measurement apparatus 100 according to the second embodiment can determine whether the subject's eye 91a is hyperopic or myopic based on the movement of the retroillumination, while also determining the degree of refractive power based on the state of the image 81 formed by the retroillumination from the retina 92a of the subject's eye 91a by the first light 18. Explaining this with reference to FIG. 4, when an image 81 formed by the retroillumination from the retina 92 ​​as shown in the column for refractive power -2 or +1 among the images formed by the diverging light flux in the middle row of FIG. 4 is obtained, it is not clear from the state of the image 81 (particularly the width of the image 81) whether the image 81 has a refractive power of -2 or +1. However, if the light is moved by the first optical system 10 and the image 81 due to the reflected light accompanies it, the refractive power is determined to be +1, and if the image 81 due to the reflected light moves backward, the refractive power is determined to be -2.

[0117] As described above, the eye refraction measurement apparatus 100 according to the second embodiment can accurately determine the refractive power even when only one type of first light 18 is incident on the test eye 91a by controlling the first optical system 10. However, even in the second embodiment, multiple types of first light 18 may be prepared and incident on the test eye 91a to determine the refractive power. Due to differences in the refractive power of the test eye 91a, it may be difficult to properly detect the difference in the image 81 when using first light 18 with a certain beam control (for example, in the example shown in FIG. 4 , the difference in size of the image 81 is difficult to see between the images −2 and −3 of the convergent beam). Therefore, by using multiple types of first light 18, the first light 18 with a beam control that makes it easier to determine the refractive power is incident on the test eye 91a, thereby improving the accuracy of the refractive power determination.

[0118] (Modification 1 of Incident Angle Control of First Light 18) Although the above describes an example in which the movement of first light 18 is controlled by reflecting mirror 13, first light 18 can also be controlled using other optical elements included in first optical system 10. For example, the angle of light source unit 15 that causes first light 18 to be incident on reflecting mirror 13 may be changed to change the angle of first light 18 emitted from light source unit 15. In other words, the angle of first light 18 incident on reflecting mirror 13 may be changed by changing any of the optical elements and devices included in first optical system 10.

[0119] Alternatively, an optical element such as filter 14 may be disposed between light source unit 15 and reflecting mirror 13, and the angle of first light 18 incident on reflecting mirror 13 may be changed by moving this element.

[0120] (Modification 2 of Incident Angle Control of First Light 18) Furthermore, when changing the angle at which the first light 18 is incident on the subject's eye 91a, the subject's eye 91a may be moved instead of controlling the first optical system 10 to move.

[0121] 1, an image that can be seen by the subject 90 is displayed on the display device 21, and the subject 90 is guided to gaze at the image. Then, by moving the image displayed on the display device 21 left or right, the orientation of the subject's eye 91a changes. This changes the orientation of the subject's eye 91a with respect to the first light 18, and therefore, the same effect as that obtained by moving the first light 18 described above can be obtained.

[0122] When moving the subject's eye 91a as described above, the subject's eye 91a may be coordinated with the non-subject's eye 91b by controlling the second light 28 incident on the non-subject's eye 91b. That is, the image on the display device 21 is made visible to the non-subject's eye 91b, and the non-subject's eye 91b is moved by moving the image left and right. As a result, the subject's eye 91a moves in coordination with the non-subject's eye 91b, and the subject's eye 91a moves, changing the angle of incidence of the first light 18 on the subject's eye 91a.

[0123] That is, changing the state of the non-subject's eye 91b by controlling the second light 28 to the non-subject's eye 91b using the second optical system 20 also includes moving the non-subject's eye 91b as described above.

[0124] The non-examined eye 91b and the examined eye 91a may be moved not only in the left-right direction but also in the up-down and diagonal directions.

[0125] Furthermore, when moving the subject's eye 91a as described above, the subject's eye 91a may be made to directly view the image. Furthermore, the eye refraction testing apparatus 100 may prompt the subject 90 to move his or her eye by audio guidance.

[0126] Embodiment 3 In the third embodiment, a description will be given of an eye refractive power determination that is different from the eye refractive power determinations performed by the eye refractive power testing apparatus 100 according to the first and second embodiments. The eye refractive power testing apparatus 100 according to the third embodiment can also determine the refractive power by changing the wavelength of the first light 18 incident on the subject's eye 91a.

[0127] The eye refractive power testing device 100 according to embodiment 3 includes a light source 11 that emits light of different wavelengths, and by switching the light source 11 that emits light, the wavelength of the first light 18 that is incident on the test eye 91a is changed.

[0128] Alternatively, the first optical system 10 may include a filter 14 that transmits only a specific wavelength of the light emitted from the light source 11. The eye refraction testing apparatus 100 may change the wavelength of the first light 18 that is incident on the subject's eye 91a by switching the filter 14.

[0129] The eye refraction measuring apparatus 100 according to the third embodiment, for example, causes first light 18 of a short wavelength (blue) and a long wavelength (red) to be incident on the subject's eye 91a, and detects the reflected light from the subject's eye 91a due to each light by the sensor 40. Light of different wavelengths is refracted differently by elements that refract light, such as the cornea 93 and the crystalline lens 94. Therefore, similar to the case where two types of light beams that have been subjected to different beam control (converging beam, diverging beam, or parallel beam) are incident on the subject's eye 91a as described in the first embodiment, images caused by the reflected light from the retina 92 ​​of the two types of light of different wavelengths are detected in different states by the sensor 40.

[0130] For example, when the first light 18 from a line light source as shown in FIG. 4 in the first embodiment is incident on the subject's eye 91a as light of two different wavelengths, the shape of the image differs depending on the refractive power of the subject's eye 91a. However, as in the case where two types of light beams with different beam control (convergent light beam, divergent light beam, or parallel light beam) are incident as described in the first embodiment, it may not be possible to determine whether the subject's eye 91a is hyperopic or myopic with light of one wavelength. In the third embodiment, the eye refraction testing device 100 causes two types of light beams with different states to be incident on the subject's eye 91a, acquires images of reflected light by each light beam with the sensor 40, and determines the refractive power of the subject's eye 91a by comparing them with a sample prepared in advance.

[0131] In the above, an example was described in which two types of light, blue and red, are incident on the subject's eye 91a, but the first light 18 only needs to have different wavelengths, and preferably the two types of light have as large a difference in wavelength as possible. Also, the first light 18 does not need to be visible light as long as it can be detected by the sensor 40.

[0132] Furthermore, the two types of light having different wavelengths may be further subjected to luminous flux control. That is, the first light 18, which has been subjected to wavelength control in addition to the different luminous flux control according to the first embodiment, may be incident on the subject's eye 91a. In this case, specimens corresponding to the first light 18 having different characteristics are prepared, and the refractive power of the subject's eye 91a is determined based on the specimens.

[0133] In the present disclosure, the light characteristics of the first light 18 include the controlled light flux described in the first embodiment, and the wavelength and light intensity described in the present embodiment.

[0134] Embodiment 4 In the fourth embodiment, an eye refraction determination will be described which is different from the eye refraction determination performed by the eye refraction testing apparatus 100 according to the first to third embodiments. The eye refraction testing apparatus 100 according to the fourth embodiment can remove or reduce the influence of reflected light from other than the retina 92 ​​from an image obtained by reflected light from the subject's eye 91a.

[0135] 4 to 6, an image 80 formed by reflected light from the subject's eye 91a detected by the sensor 40 may include images 82 and 83 of reflected light from sources other than the retina 92, such as the cornea 93 and the crystalline lens 94. The eye refractive power testing apparatus 100 according to the fourth embodiment can eliminate or reduce these images of reflected light from sources other than the retina 92.

[0136] (Noise reduction or removal by polarizing filter 16) 11 is a schematic diagram illustrating the structure of an eye refraction measurement apparatus 100 according to embodiment 4. In the eye refraction measurement apparatus 100 according to embodiment 4, a polarizing filter 16 is arranged on the optical path along which reflected light 19 enters a sensor 40.

[0137] The polarizing filter 16 is selected so as to transmit light reflected from the retina 92 ​​and reduce or eliminate light reflected from other elements, such as the cornea 93 and lens 94. Light may become polarized upon reflection. The polarization state of light reflected from the retina 92 ​​may differ from that of the cornea 93 and lens 94. For example, light reflected from the surface of the cornea 93 is polarized when reflected at Brewster's angle (approximately 53 degrees). This is because the surface of the cornea 93 is smooth, making reflected light more likely to be polarized at certain angles of incidence.

[0138] Even if the angle of light incident on the cornea 93 is small, if the light is incident at a certain angle, the light will be polarized, and in this case the polarizing filter 16 can reduce the light reflected from the cornea 93 and allow the light to enter the sensor 40. If the angle of incidence is away from the Brewster's angle, the degree of polarization may be small, but by controlling the eyeball movement or the beam of the first light 18 as described in the first embodiment to bring the angle of incidence on the cornea 93 closer to the Brewster's angle, the influence of the light reflected from the cornea 93 can be reduced. This is also true for other elements of the subject's eye 91a, such as the crystalline lens 94, but the Brewster's angle varies depending on the refractive index of those elements.

[0139] The polarizing filter 16 described above may be replaced with other optical elements. For example, a polarizing beam splitter may be used. Also, the reflecting mirror 13 may be replaced with a polarizing beam splitter.

[0140] (Noise reduction or removal using TOF range images) The noise of the reflected light 19 can also be reduced or removed using a TOF distance image. In the eye refraction testing apparatus 100 according to the fourth embodiment, the positional relationship between the sensor 40 and the subject's eye 91a can be kept substantially constant, and therefore the distances between the sensor 40 and the retina 92, cornea 93, and crystalline lens 94 can also be kept substantially constant. In the eye refraction testing apparatus 100, the sensor 40 only needs to detect reflected light at a distance where the retina 92 ​​is located.

[0141] For example, the eye refraction testing device 100 detects reflected light by illuminating a first light 18 from a light source 11 onto the subject's eye 91a and detecting the reflected light with a sensor 40. This measures the time of flight of the light from reaching the subject's eye 91a to being reflected from the retina 92 ​​and returning. At this time, the time taken for the light to be reflected from other parts such as the cornea 93 and the crystalline lens 94 is also measured. The eye refraction testing device 100 obtains an image 81 due to reflected light from the retina 92 ​​by extracting only the light corresponding to the distance to the retina 92 ​​from the reflected light detected by the sensor 40.

[0142] (Noise reduction or removal by image processing) Image processing can also be used to reduce or remove noise from the reflected light 19. The eye refraction testing apparatus 100 according to the fourth embodiment can obtain images 81, 82, and 83 shown in Fig. 2 and the like as images using the sensor 40, and it is possible to extract only the image 81 from this image based on a specific shape or size, and remove or reduce the other images 82 and 83 from the data.

[0143] As described above, the eye refraction testing apparatus 100 can obtain the state of the image 81 more accurately by removing or reducing reflected light from areas other than the retina 92. Therefore, the eye refraction testing apparatus 100 can more accurately compare the sample with the image 81 actually measured by the sensor 40, improving the accuracy of refractive power determination.

[0144] When noise such as reflected light from sources other than the retina 92 ​​is removed or reduced by using the TOF image and image processing described above, the eye refraction testing apparatus 100 further includes an image processing unit, and the image processing unit removes or reduces noise. The image processing unit may be included in the control device 50.

[0145] The above-described techniques for improving the accuracy of the image 81 through processing such as filtering, TOF imaging, and image processing are merely examples, and they may be combined with each other or may be combined with other known techniques.

[0146] Although the present disclosure has been described above based on the embodiments, the present disclosure is not limited to the configurations of the above-described embodiments. In the above-described embodiments, the eye refraction testing apparatus 100 is realized using the structure shown in FIG. 1 . However, other structures may be used as long as the positional relationships between the first optical system 10, the second optical system 20, and the sensor 40 and the test eye 91a and the non-test eye 91b can be maintained constant during refractive power determination. Furthermore, the eye refraction testing method implemented by the eye refraction testing apparatus 100 can be realized not only by the eye refraction testing apparatus 100 shown in the embodiments, but also using other devices and equipment. Furthermore, at least some of the functions of the eye refraction testing apparatus 100 can be realized by installing a computer program in various computers or various communication terminals and mobile information terminals. In other words, the present disclosure also includes programs for causing various computers to function as at least part of the eye refraction testing apparatus 100. Furthermore, the above-described embodiments and variations may be implemented in appropriate combinations. It should be noted that the gist (technical scope) of this disclosure also encompasses various modifications, applications, and uses that may be made by those skilled in the art as needed.

[0147] The eye refractive power testing apparatus 100 described above may also include combinations of the features shown in the following Supplementary Notes 1 to 25. These combinations are described below. [Appendix 1] a first optical system capable of generating a plurality of types of light having different characteristics and directing the light into an eye to be examined, which is one of both eyes of a subject; a sensor for detecting reflected light from the subject's eye; a determiner for determining the refractive power of the subject's eye, The sensor Detecting the image formed by the retroillumination; The determiner is determining the refractive power of the subject's eye based on the shape of the image; Eye refraction testing device. [Appendix 2] 10. The eye refractive power testing apparatus according to claim 1, The image is The first optical system includes a plurality of images formed by reflected light from each of a plurality of types of light incident thereon, The determiner is determining the refractive power of the subject's eye based on the shapes of the respective images detected by the sensor; Eye refraction testing device. [Appendix 3] 10. The eye refractive power testing apparatus according to claim 2, The determiner is comparing a pre-stored sample of images of the subject's eye obtained by reflection illumination with the plurality of images obtained by the sensor to determine the refractive power of the subject's eye; Eye refraction testing device. [Appendix 4] An eye refractive power testing apparatus according to any one of appendices 1 to 3, a second optical system that, when light incident on the subject's eye from the first optical system is defined as first light, causes second light different from the first light to be incident on the other eye of the subject that is not to be examined, The second optical system is controlling the second light to change the state of the non-examined eye; Eye refraction testing device. [Appendix 5] a first optical system capable of generating a plurality of types of light having different characteristics and causing the light to be incident as a first light on a test eye, which is one of both eyes of a test subject; a second optical system that causes second light from a light source different from the first light to be incident on the other eye of the subject, which is the eye not to be examined; a sensor that detects reflected light from the subject's eye due to the first light, The sensor Detecting the image formed by the retroillumination; The second optical system is controlling the second light to change the state of the non-examined eye; Eye refraction testing device. [Appendix 6] 6. The eye refractive power testing apparatus according to claim 4 or 5, The second optical system is a display device for displaying an image; Eye refraction testing device. [Appendix 7] 7. The eye refractive power testing apparatus according to claim 6, The display device and the sensor are It is equipped in an integrated mobile information terminal, Eye refraction testing device. [Appendix 8] The eye refractive power testing apparatus according to claim 6 or 7, The display device includes: changing the state of the non-examined eye by moving the displayed image; Eye refraction testing device. [Appendix 9] An eye refractive power testing apparatus according to any one of appendices 1 to 3, further comprising an audio playback device; The audio playback device Change the orientation of the subject's eye with voice guidance. Eye refraction testing device. [Appendix 10] An eye refractive power testing apparatus according to any one of appendices 1 to 9, a support structure for supporting the first optical system; The first optical system is a light source that emits light in a first direction; an optical path separating means for separating light in a second direction intersecting the first direction, The optical path separating means The optical system is configured to guide light from a light source to the subject's eye and guide reflected light from the subject's eye to the sensor, The support structure includes: The eye to be examined is configured to be positionable relative to the sensor. Eye refraction testing device. [Appendix 11] 11. The eye refractive power testing apparatus according to claim 10, The support structure includes: The eye to be examined can be positioned by contacting the head of the examinee. Eye refraction testing device. [Appendix 12] 12. The eye refractive power testing apparatus according to claim 11, The support structure includes: The eye to be examined is positioned on an extension line extending from the sensor through the optical path separating means in the second direction. Eye refraction testing device. [Appendix 13] An eye refractive power testing apparatus according to any one of appendices 10 to 12, The optical path separating means The angle of the second direction relative to the first direction is changeable. Eye refraction testing device. [Appendix 14] An eye refractive power testing apparatus according to any one of appendices 10 to 13, The optical path separating means It is composed of a mirror that reflects some of the incident light and transmits some of the incident light. Eye refraction testing device. [Appendix 15] An eye refractive power testing apparatus according to any one of appendices 10 to 14, The light source is The angle of the second direction relative to the first direction is changeable. Eye refraction testing device. [Appendix 16] 16. The eye refractive power testing apparatus according to claim 15, The light source is The angle of light incident on the optical path separating means is changeable. Eye refraction testing device. [Appendix 17] An eye refractive power testing apparatus according to any one of appendices 10 to 16, The light source is The wavelength of the light to be emitted can be changed. Eye refraction testing device. [Appendix 18] An eye refractive power testing apparatus according to any one of appendices 10 to 17, Any of the optical elements located between the eye to be examined and the sensor is It is configured to reduce the reflected light from the cornea among the reflected light from the subject's eye. Eye refraction testing device. [Appendix 19] 19. The eye refractive power testing apparatus according to claim 18, a polarizing filter is further provided between the subject's eye and the sensor; Eye refraction testing device. [Appendix 20] 19. The eye refractive power testing apparatus according to claim 18, further comprising an image processing unit that processes the image captured by the sensor, The image processing unit TOF distance images reduce the influence of reflected light from sources other than the retina of the subject's eye. Eye refraction testing device. [Appendix 21] 19. The eye refractive power testing apparatus according to claim 18, an image processing unit that processes the image captured by the sensor, The image processing unit Reduces the effects of corneal retroillumination. Eye refraction testing device. [Appendix 22] The light having controlled characteristics is incident on one of the examinee's eyes, determining the refractive power of the subject's eye based on the shapes of a plurality of images formed by retroillumination of the subject's eye using a plurality of types of light with different characteristics; Eye refraction testing method. [Appendix 23] 23. The method for examining eye refraction according to claim 22, comparing the plurality of images with a pre-stored sample to determine the refractive power of the subject's eye; Eye refraction testing method. [Appendix 24] 24. The eye refractive power testing method according to claim 22 or 23, a second light source different from the first light incident on the subject's eye is incident on the other eye of the subject, that is, the non-subject eye; controlling the second light to change the state of the non-examined eye, and detecting the reflected light caused by the first light to determine the refractive power of the examined eye; Eye refraction testing method. [Appendix 25] a second light source different from the first light incident on the subject's eye is incident on the other eye of the subject that is not the subject's eye; controlling the second light to change the state of the non-examined eye, and detecting the reflected light caused by the first light to determine the refractive power of the examined eye; Eye refraction testing method. [Explanation of symbols]

[0148] 10:1st optical system 11:Light source 12: Lens 13:Reflector 13a: Rotation axis 13b: Mirror 14: Filter 15: Light source unit 16: Polarizing filter 18:First light 19:Reflection 20:Second optical system 21:Display device 22: Lens 28:Second light 30:Support structure 31: Contact surface 40: Sensor 50: Control device 51: Control unit 52: Judgment device 53: Image acquisition part 54: Storage section 55: Output section 60: Mobile information terminal 61: CPU 62: Storage device 63: Communication devices 64: Input device 65: Output device 67: Imaging device 80~84: Statue 90: Subject 91: Examined eye 91a: Test eye 91b: Non-tested eye 92: Retina 92a: retina 93 :Cornea 94: Crystalline lens 94a: Crystalline lens 94b: Crystalline lens 95: Pupil 100: Eye refractive power testing device

Claims

1. a first optical system capable of generating a plurality of types of light having different characteristics and directing the light into an eye to be examined, which is one of both eyes of a subject; a sensor for detecting reflected light from the subject's eye; a determiner for determining the refractive power of the subject's eye, The sensor Detecting the image formed by the retroillumination; The determiner is determining the refractive power of the subject's eye based on the shape of the image; Eye refraction testing device.

2. The eye refractive power testing apparatus according to claim 1, The image is The first optical system includes a plurality of images formed by reflected light from each of a plurality of types of light incident thereon, The determiner is determining the refractive power of the subject's eye based on the shapes of the respective images detected by the sensor; Eye refraction testing device.

3. 3. The eye refractive power testing apparatus according to claim 2, The determiner is comparing a pre-stored sample of images of the subject's eye obtained by reflection illumination with the plurality of images obtained by the sensor to determine the refractive power of the subject's eye; Eye refraction testing device.

4. The eye refractive power testing apparatus according to claim 1, a second optical system that, when light incident on the subject's eye from the first optical system is defined as first light, causes second light different from the first light to be incident on the other eye of the subject, which is a non-subject's eye; The second optical system is controlling the second light to change the state of the non-examined eye; Eye refraction testing device.

5. a first optical system capable of generating a plurality of types of light having different characteristics and causing the light to be incident as first light on a test eye, which is one of both eyes of a test subject; a second optical system that causes second light from a light source different from the first light to be incident on the other eye of the subject, which is the eye not to be examined; a sensor that detects reflected light from the subject's eye due to the first light, The sensor Detecting the image formed by the retroillumination; The second optical system is controlling the second light to change the state of the non-examined eye; Eye refraction testing device.

6. 6. The eye refractive power testing apparatus according to claim 4 or 5, The second optical system is a display device for displaying an image; Eye refraction testing device.

7. 7. The eye refractive power testing apparatus according to claim 6, The display device and the sensor are It is equipped in an integrated mobile information terminal, Eye refraction testing device.

8. 7. The eye refractive power testing apparatus according to claim 6, The display device includes: changing the state of the non-examined eye by moving the displayed image; Eye refraction testing device.

9. The eye refractive power testing apparatus according to any one of claims 1 to 3, further comprising an audio playback device; The audio playback device Change the orientation of the subject's eye with voice guidance. Eye refraction testing device.

10. The eye refractive power testing apparatus according to any one of claims 1 to 5, a support structure for supporting the first optical system; The first optical system is a light source that emits light in a first direction; an optical path separating means for separating light in a second direction intersecting the first direction, The optical path separating means The optical system is configured to guide light from a light source to the subject's eye and guide reflected light from the subject's eye to the sensor, The support structure includes: The eye to be examined is configured to be positionable relative to the sensor. Eye refraction testing device.

11. The eye refractive power testing apparatus according to claim 10, The support structure includes: The eye to be examined can be positioned by contacting the head of the examinee. Eye refraction testing device.

12. The eye refractive power testing apparatus according to claim 11, The support structure includes: The eye to be examined is positioned on an extension line extending from the sensor through the optical path separating means in the second direction. Eye refraction testing device.

13. The eye refractive power testing apparatus according to claim 10, The optical path separating means The angle of the second direction relative to the first direction is changeable. Eye refraction testing device.

14. The eye refractive power testing apparatus according to claim 10, The optical path separating means It is composed of a mirror that reflects some of the incident light and transmits some of the incident light. Eye refraction testing device.

15. The eye refractive power testing apparatus according to claim 10, The light source is The angle of the second direction relative to the first direction is changeable. Eye refraction testing device.

16. 16. The eye refractive power testing apparatus according to claim 15, The light source is The angle of light incident on the optical path separating means is changeable. Eye refraction testing device.

17. The eye refractive power testing apparatus according to claim 10, The light source is The wavelength of the light to be emitted can be changed. Eye refraction testing device.

18. The eye refractive power testing apparatus according to claim 10, Any of the optical elements located between the eye to be examined and the sensor is It is configured to reduce the reflected light from the cornea among the reflected light from the subject's eye. Eye refraction testing device.

19. 19. The eye refractive power testing apparatus according to claim 18, a polarizing filter is further provided between the subject's eye and the sensor; Eye refraction testing device.

20. 19. The eye refractive power testing apparatus according to claim 18, further comprising an image processing unit that processes the image captured by the sensor, The image processing unit The TOF distance image reduces the influence of reflected light from sources other than the retina of the subject's eye. Eye refraction testing device.

21. 19. The eye refractive power testing apparatus according to claim 18, an image processing unit that processes the image captured by the sensor, The image processing unit Reduces the effects of corneal retroillumination. Eye refraction testing device.

22. The light having controlled characteristics is incident on one of the examinee's eyes, determining the refractive power of the subject's eye based on the shapes of a plurality of images formed by retroillumination of the subject's eye using a plurality of types of light with different characteristics; Eye refraction testing method.

23. 23. The method for examining eye refraction according to claim 22, comparing the plurality of images with a pre-stored sample to determine the refractive power of the subject's eye; Eye refraction testing method.

24. 24. The method for examining eye refraction according to claim 22 or 23, a second light source different from the first light incident on the subject's eye is incident on the other eye of the subject, the other eye being a non-subject eye; controlling the second light to change the state of the non-examined eye, and detecting the reflected light caused by the first light to determine the refractive power of the examined eye; Eye refraction testing method.

25. a second light source different from the first light incident on the subject's eye is incident on the other eye of the subject that is not the subject's eye; controlling the second light to change the state of the non-examined eye, and detecting the reflected light caused by the first light to determine the refractive power of the examined eye; Eye refraction testing method.

Images