Subjective optometry device and subjective optometry program

Abstract

To provide a subjective optometer and a subjective optometric program capable of executing an addition examination on an eye to be examined accurately.SOLUTION: A subjective optometer for subjectively measuring eye refractive power of an eye to be examined includes: correction means disposed in front of the eye to be examined for changing optical characteristics of a target light beam; acquisition means for acquiring at least a cylindrical correction quantity and an astigmatism axis correction quantity for the eye to be examined; and control means for controlling the correction means. The correction means includes a Stokes lens including a first cylindrical lens and a second cylindrical lens. The control means changes a composite axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction quantity and the astigmatism axis correction quantity in an addition examination on the eye to be examined. The composite axis angle is an axis angle taking into account a deviation amount of the astigmatism axis correction quantity that occurs when assuming that an optical member and a cross cylinder lens are arranged for correcting the eye to be examined by the cylindrical correction quantity and the astigmatism axis correction quantity.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a subjective refractometer and a subjective refraction program for automatically measuring the refractive power of an eye to be examined.

Background Art

[0002] There is known a subjective refractometer that measures the refractive power of an eye to be examined by placing an optical member in front of the subject's eye and presenting a test target that has passed through the optical member to the eye to be examined. In Patent Document 1, by using two cylindrical lenses having the same absolute value of focal length and different signs as the optical member and changing the cylindrical refractive power and the astigmatic axis angle of the target light beam, the cylindrical correction amount and the astigmatic axis correction amount for correcting the eye to be examined are changed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the subjective measurement of an eye to be examined, a participation degree inspection for adding a participation degree to the correction amount at a predetermined inspection distance of the eye to be examined may be performed. However, when the two cylindrical lenses are combined, a deviation may occur in the spherical correction amount of the eye to be examined, and there is a possibility that an accurate participation degree cannot be obtained.

[0005] In view of the above prior art, it is a technical problem of the present disclosure to provide a subjective refractometer and a subjective refraction program that can accurately perform the participation degree inspection of an eye to be examined.

Means for Solving the Problems

[0006] In order to solve the above problems, the present disclosure is characterized by including the following configuration. (1) A subjective ophthalmoscopic device according to a first aspect of the present disclosure is a subjective ophthalmoscopic device for subjectively measuring the refractive power of an eye to be examined, the device being placed in front of the eye to be examined and having a target presenting means vision The device comprises a corrective means for changing the optical properties of a target beam, an acquisition means for acquiring at least a cylindrical correction amount and an astigmatism axis correction amount for the eye under examination, and a control means for controlling the corrective means, wherein the corrective means has a Stokes lens including a first cylindrical lens and a second cylindrical lens that can rotate independently in front of the eye, and the control means controls the Stokes lens in an add power test to measure the add power for the correction amount at a predetermined test distance of the eye under examination, and changes the combined axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction amount and the astigmatism axis correction amount, wherein the combined axis angle is an axis angle that takes into account the amount of deviation of the astigmatism axis correction amount that occurs when an optical member and a cross cylinder lens are assumed to be arranged in order to correct the eye under examination by the cylindrical correction amount and the astigmatism axis correction amount. (2) A subjective optometry program according to a second aspect of the present disclosure is a subjective optometry program for use in a subjective optometry device for subjectively measuring the refractive power of an eye, comprising a Stokes lens including a first cylindrical lens and a second cylindrical lens that are independently rotatable in front of the eye, and which is a corrective means that changes the optical properties of a target beam emitted from a target presentation means, and which is executed by the processor of the subjective optometry device, comprising an acquisition step of acquiring at least a cylindrical correction amount and an astigmatism axis correction amount of the eye to be examined, and a control step of controlling the corrective means The control step involves causing the subjective optometry device to perform the following steps: In an add power test that measures the add power relative to the correction amount of the eye under test at a predetermined test distance, the control step involves controlling the Stokes lens to change the combined axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction amount and the astigmatism axis correction amount, wherein the combined axis angle is an axis angle that takes into account the amount of deviation of the astigmatism axis correction amount that occurs when assuming the arrangement of optical members and a cross cylinder lens in order to correct the eye under test by the cylindrical correction amount and the astigmatism axis correction amount. [Brief explanation of the drawing]

[0007] [Figure 1] This is an external view of a subjective optometry device. [Figure 2] This is a schematic diagram of the light projection optical system. [Figure 3] This is a schematic diagram of the eye refractive power measurement unit. [Figure 4] This is a schematic diagram of the lens unit. [Figure 5] This is a schematic diagram of a conventional lens unit. [Figure 6] This diagram shows the change in the combined refractive power of the cylindrical lens and the cross-cylinder lens in a cylindrical lens disk. [Figure 7] This is a schematic diagram of the control system for a subjective optometry device. [Figure 8] This diagram shows the change in the combined refractive power of the cylindrical lens and the cross-cylinder lens in a cylindrical lens disk. [Modes for carrying out the invention]

[0008] <Overview> An overview of the subjective optometry device according to the embodiments of this disclosure will be described. In this embodiment, the left-right direction of the subjective optometry device is the X direction, the up-down direction is the Y direction, and the front-back direction (working distance direction) is the Z direction. The reference numerals L and R indicate the left eye and right eye, respectively. The items classified in <> below may be used independently or in relation to each other.

[0009] The subjective optometry device of this embodiment (for example, subjective optometry device 100) is a device for subjectively measuring the refractive power of the eye being examined. For example, the refractive power of the eye being examined may be measured as at least one of the following: spherical refractive power, cylindrical refractive power, astigmatism axis angle, etc. Of course, in addition to refractive power, the subjective optometry device may also measure binocular vision function (for example, at least one of the following: prism amount, stereopsis function, etc.), contrast sensitivity, etc.

[0010] In this embodiment, the subjective optometry device is given as an example of a configuration that includes a target presentation means and a correction means as described later, but is not limited to this. The subjective optometry device may have at least a correction means. For example, it may have only a correction means, or it may have a target presentation means and a correction means as a system.

[0011] The subjective optometry device of this embodiment may include a target presentation means. The target presentation means emits a target light beam toward the eye to be examined.

[0012] For example, the target presentation means may be a display (e.g., display 31). Alternatively, for example, the target presentation means may be a light source and a DMD (Digital Micromirror Device). Alternatively, for example, the target presentation means may be a light source and a target board.

[0013] For example, the target light beam from the target presentation means may be guided directly toward the eye under examination. Alternatively, for example, the target light beam from the target presentation means may be guided toward the eye under examination via a light projection optical system (e.g., light projection optical system 30). For example, the light projection optical system may have at least one optical element for passing the target light beam emitted from the target presentation means. As an example, it may have at least one of a lens, a mirror, etc.

[0014] The subjective optometry device of this embodiment may include a corrective means. The corrective means is placed in front of the eye under examination and alters the optical properties of the target light beam emitted from the target presentation means.

[0015] The correction means may have a configuration that can change at least any one of the optical characteristics such as the spherical refractive power, cylindrical refractive power, and astigmatic axis angle in the target beam. As an example, the correction means may be an eye refractive power measurement unit (for example, the eye refractive power measurement unit 40) that switches and arranges an optical member (for example, the optical element 51) through an inspection window (for example, the inspection window 43) in front of the eye to be examined. For example, the optical member may be at least any one of a spherical lens, a cylindrical lens, a variable focus lens, a cross cylinder lens, a rotary prism, a wavefront modulation element, and the like. Of course, the optical member may be different from these. Further, for example, the eye refractive power measurement unit may have a lens disk (for example, the lens disk 50) on which a plurality of optical members are arranged on the same circumference. In this case, the optical characteristics of the target beam are changed by controlling the driving means (for example, the driving units 52, 53, etc.) for controlling the lens disk.

[0016] <Change in the spherical refractive power of the target beam> In the present embodiment, the correction means may include a first correction means for changing the spherical refractive power of the target beam by using a variable optical member with a variable focal length, and a second correction means for switching and arranging the optical members to change the spherical refractive power of the target beam.

[0017] The first correction means is configured to change the spherical refractive power of the target beam by changing the focal length of the variable focus member in a state where the variable focus member is arranged in the optical path of the target beam. For example, the first correction means may switch and arrange the variable focus member in front of the eye to be examined. As an example, in this case, the variable focus member may be provided on the lens disk of the eye refractive power measurement unit. Further, for example, the first correction means may fixedly arrange the variable focus member in front of the eye to be examined. As an example, in this case, the variable focus member may always be arranged on the inspection window of the eye refractive power measurement unit. For example, there may be one or a plurality of variable focus members. For example, the variable focus member may be a variable focus lens. As the variable focus lens, at least any one of a liquid lens, a liquid crystal lens, an Alvarez lens, and the like can be used.

[0018] The first correction means may be capable of changing the spherical refractive power of the target light beam within the range of the first refractive power by using a variable focus member. That is, it may be possible to continuously change the spherical refractive power of the target light beam by using a variable focus member.

[0019] The second correction means is configured to change the spherical refractive power of the target light beam by switching an optical member disposed in the optical path of the target light beam. For example, the second correction means may switch and dispose an optical member in front of the eye to be examined. As an example, in this case, an optical member may be provided on the lens disk of the eye refractive power measurement unit. For example, the second optical element may be one or a plurality. For example, the optical member may be a spherical lens. When a variable focus member is used as the optical member of the second correction means, the focal length of the variable focus member may be set to a fixed distance.

[0020] The step in which the first correction means can change the spherical refractive power of the target light beam may be configured to be smaller than the step in which the second correction means can change the spherical refractive power of the target light beam. For example, in the first correction means, the spherical refractive power of the target light beam may be changed in units of 0.25 D or less, and in the second correction means, the spherical refractive power of the target light beam may be changed in units larger than 0.25 D. Of course, the value of the step of the spherical refractive power is an example and may be different. Thereby, the spherical refractive power of the target light beam can be continuously changed within the range of the first refractive power by using the first correction means. Further, by using the first correction means and the second correction means in combination, it becomes possible to expand the spherical refractive power of the target light beam to a range of a combined spherical refractive power wider than the first refractive power, and the spherical refractive power of the target light beam can be continuously changed within the range of the combined refractive power.

[0021] The subjective optometry device of this embodiment may include a determination means (for example, a control unit 70). The determination means determines whether or not to place the optical member of the second corrective means in front of the eye under examination based on the modified spherical refractive power, which is the spherical refractive power of the target light beam. In other words, it determines whether or not to place the optical member of the second corrective means in front of the eye under examination based on the amount of spherical correction for correcting the eye under examination, which can be changed by changing the spherical refractive power of the target light beam. For example, the determination means may determine whether or not to place the optical member based on whether or not the modified spherical refractive power of the target light beam exceeds a predetermined threshold that has been set in advance. For example, the predetermined threshold may be a fixed value, or the examiner may set an arbitrary value. This allows the variable focus member of the first corrective means and the optical member of the second corrective means to be appropriately combined as needed.

[0022] The determination means may determine whether or not to place the optical member of the second corrective means in front of the eye under examination based on the modified spherical refractive power of the target light beam and the range of the first refractive power of the first corrective means. In this case, the threshold of the modified spherical refractive power of the target light beam may be set based on the range of the first refractive power of the first corrective means. For example, the predetermined threshold may be the range from the maximum value to the minimum value of the first refractive power of the first corrective means. Alternatively, for example, the predetermined threshold may be the range from the values ​​around the maximum value to the values ​​around the minimum value of the first refractive power of the first corrective means. As an example, it may be the range from a value one step smaller than the maximum value of the first refractive power to a value one step larger than the minimum value. This makes it easy to identify cases where adjustment of the spherical refractive power of the target light beam using the first corrective means alone is insufficient, such as when the amount of spherical correction of the eye under examination is high, and allows for an appropriate combination of the variable focus member of the first corrective means and the optical member of the second corrective means.

[0023] The subjective optometry device of this embodiment may include a control means (for example, a control unit 70). The control means controls the correction means. For example, the control means controls the first correction means and the second correction means to change the spherical refractive power of the target light beam. For example, by changing the spherical refractive power of the target light beam, the amount of spherical correction for correcting the eye under examination is changed. As a result, the spherical refractive power of the target light beam changes seamlessly (without seams), reducing the discomfort caused by the shift in the spherical refractive power of the target light beam from a first modified spherical refractive power to a second modified spherical refractive power different from the first modified spherical refractive power (in other words, the amount of spherical correction of the eye under examination switches from a first spherical correction amount to a second spherical correction amount), and enabling accurate measurement of the refractive power of the eye under examination.

[0024] The control means may change the spherical refractive power of the target light beam and the amount of spherical correction of the eye under examination by arranging the variable focal member of the first correction means in the optical path of the target light beam and changing the focal length of the variable focal member. For example, the control means may rotate the lens disk of the eye refractive power measurement unit to position the variable focal member on the lens disk in the examination window (i.e., in the optical path of the target light beam). Alternatively, for example, the control means may change the focal length of the variable focal member in the examination window of the eye refractive power measurement unit.

[0025] The control means may change the spherical refractive power of the target light beam and thereby change the amount of spherical correction of the eye under examination by placing a predetermined optical member of the second correction means in the optical path of the target light beam. For example, the control means may rotate the lens disk of the eye refractive power measurement unit to position the optical member on the lens disk in the examination window (i.e., in the optical path of the target light beam).

[0026] For example, when changing the spherical refractive power of the target light beam using the variable focal member of the first corrective means, the variable focal member of the first corrective means may be placed in the optical path of the target light beam, while the optical member of the second corrective means is removed from the optical path of the target light beam, and the variable focal member may be changed to a predetermined focal length. Alternatively, when changing the spherical refractive power of the target light beam using the optical member of the second corrective means, the variable focal member of the first corrective means may be removed from the optical path of the target light beam, while the optical member of the second corrective means is placed in the optical path of the target light beam. Or, with both the variable focal member of the first corrective means and the optical member of the second corrective means placed in the optical path of the target light beam, the variable focal member may be changed to a focal length where the focal length is 0D.

[0027] Of course, for example, when changing the spherical refractive power of the target beam by combining the variable focal member of the first corrective means and the optical member of the second corrective means, the variable focal member may be changed to a predetermined focal length while both the variable focal member and the optical member are positioned in the optical path of the target beam. By combining the variable focal member and the optical member, it is possible to significantly change the spherical refractive power of the target beam. Therefore, even when the amount of spherical correction of the eye under examination is large, the refractive power of the eye under examination can be measured with high accuracy.

[0028] The control means may arrange at least the optical members of the second correction means based on the modified spherical refractive power, which is the spherical refractive power of the target light beam. That is, the control means may arrange only the optical members of the second correction means based on the modified spherical refractive power of the target light beam, or it may adjust the variable focus member of the first correction means and arrange the optical members of the second correction means.

[0029] For example, the control means may control at least the second correction means to switch and arrange the optical members when the changing spherical refractive power of the target light beam exceeds the range of the first refractive power in the first correction means. In other words, at least the optical members may be arranged in at least one of the cases where the changing spherical refractive power of the target light beam exceeds the maximum value of the first refractive power of the first correction means, or exceeds the minimum value of the first refractive power. Also, for example, the control means may arrange at least the optical members in at least one of the cases where the changing spherical refractive power of the target light beam is within the range of the first refractive power of the spherical refractive power in the first correction means, and exceeds a value around the maximum value of the first refractive power, or exceeds a value around the minimum value of the first refractive power.

[0030] The control means may adjust the variable focus member of the first corrective means using a table or calculation formula that associates the changed spherical refractive power of the target light beam with the first refractive power of the first corrective means. The control means may also set whether or not to position the optical member of the second corrective means using a table or calculation formula that associates the changed spherical refractive power of the target light beam with the second refractive power of the second corrective means. Of course, the control means may also perform the adjustment of the variable focus member of the first corrective means and the setting of whether or not to position the optical member of the second corrective means using a table or calculation formula that associates the changed spherical refractive power of the target light beam with the first refractive power of the first corrective means and the second refractive power of the second corrective means. For example, such a table may be determined in advance through experiments or simulations and stored in a memory means.

[0031] The control means may control at least the second correction means and switch the optical members based on the determination result of the aforementioned determination means. For example, if the control means determines that the amount of change in the spherical refractive power of the target light beam does not exceed a predetermined threshold, it may control the first correction means and generate a predetermined spherical refractive power using a variable focus member. Alternatively, if the control means determines that the amount of change in the spherical refractive power of the target light beam exceeds a predetermined threshold, it may control at least the second correction means and generate a predetermined spherical refractive power using at least an optical member. Furthermore, depending on the amount of change in the spherical refractive power of the target light beam, both the first and second correction means may be controlled to generate a predetermined spherical refractive power using a variable focus member and an optical member. This allows for accurate measurement of the refractive power of the eye under examination.

[0032] When the control means adjusts the modified spherical refractive power of the target light beam from a first modified spherical refractive power to a second modified spherical refractive power different from the first modified spherical refractive power, it may control only the first correction means and change the focal length of the variable focal member according to the amount of change between the first modified spherical refractive power and the second modified spherical refractive power. For example, if the amount of change between the first modified spherical refractive power before changing the spherical refractive power of the target light beam and the second modified spherical refractive power after changing is less than or equal to a predetermined threshold, only the first correction means may be controlled. Alternatively, for example, if the amount of change between the first modified spherical refractive power and the second modified spherical refractive power exceeds a predetermined threshold, the first and second correction means, or only the second correction means, may be controlled. For example, the predetermined threshold may be a fixed value, or the examiner may set an arbitrary value. This makes it easy to adjust the spherical correction power required for correcting the eye under examination and to smoothly measure the refractive power of the eye under examination.

[0033] <Changing the cylindrical refractive power and astigmatism axis angle of the target light beam> In this embodiment, the corrective means may include a Stokes lens comprising a first cylindrical lens and a second cylindrical lens that can rotate independently in front of the eye under examination. For example, the corrective means may be able to continuously change the cylindrical refractive power of the target light beam by rotating the first and second cylindrical lenses independently to change the relative angle of the astigmatic axes of each cylindrical lens. Alternatively, for example, the corrective means may be able to continuously change the astigmatic axis angle of the target light beam by rotating the first and second cylindrical lenses integrally to change the combined axis angle of each cylindrical lens. For example, the first and second cylindrical lenses may consist of two positive cylindrical lenses with equal focal lengths, or they may consist of a positive and a negative cylindrical lens with equal focal lengths.

[0034] The corrective means may include a corrective optical member for correcting the amount of deviation in the spherical correction amount of the eye under examination, which occurs when the first cylindrical lens and the second cylindrical lens are aligned to the combined axis angle. For example, the corrective optical member may be a member capable of changing the spherical refractive power of the target light beam. As an example, at least one of the following may be used: a variable focal length member, an optical member with a constant focal length, etc. Also, for example, there may be one corrective optical member or multiple members.

[0035] For example, the corrective means may switch the placement of the corrective optical member in front of the eye being examined. In this case, for example, the corrective optical member may be provided on the lens disc of the eye's refractive power measurement unit. Such a corrective optical member may be at least one of a variable focus member (e.g., a variable focus lens), an optical member (e.g., a spherical lens), etc. Alternatively, for example, the corrective means may permanently position the corrective optical member in front of the eye being examined. In this case, for example, the corrective optical member may always be positioned in the inspection window of the eye's refractive power measurement unit. Such a corrective optical member may be a variable focus member (e.g., a variable focus lens).

[0036] The corrective means may include a corrective optical member for correcting the amount of spherical correction of the eye under examination. For example, the corrective optical member may be a member capable of changing the spherical refractive power of the target light beam. As an example, at least one of the following may be used: a variable focal length member, an optical member with a constant focal length, etc. Also, for example, there may be one corrective optical member or multiple members.

[0037] For example, the corrective means may switch the placement of the corrective optical member in front of the eye being examined. In this case, for example, the corrective optical member may be provided on the lens disc of the eye's refractive power measurement unit. Such a corrective optical member may be at least one of a variable focus member (e.g., a variable focus lens), an optical member (e.g., a spherical lens), etc. Alternatively, for example, the corrective means may permanently position the corrective optical member in front of the eye being examined. In this case, for example, the corrective optical member may always be positioned in the examination window of the eye's refractive power measurement unit. Such a corrective optical member may be a variable focus member (e.g., a variable focus lens).

[0038] In this embodiment, the corrective optical member for correcting the amount of spherical correction that occurs when the first cylindrical lens and the second cylindrical lens of the Stokes lens are aligned to the composite axis angle, and the corrective optical member for adjusting the amount of spherical correction for correcting the eye under examination, may be used for both purposes.

[0039] Furthermore, in this embodiment, the corrective optical member for correcting the deviation in the amount of spherical correction of the eye under examination and the variable focal length member of the first corrective means may be used interchangeably, or the corrective optical member for correcting the deviation in the amount of spherical correction of the eye under examination and the optical member of the second corrective means may be used interchangeably. Similarly, in this embodiment, the corrective optical member for adjusting the amount of spherical correction of the eye under examination and the variable focal length member of the first corrective means may be used interchangeably, or the corrective optical member for adjusting the amount of spherical correction of the eye under examination and the optical member of the second corrective means may be used interchangeably. This makes it possible to easily adjust the amount of spherical correction of the eye under examination.

[0040] The subjective optometry device of this embodiment may include an acquisition means (for example, a control unit 70). The acquisition means acquires at least the cylindrical correction amount and the astigmatism axis correction amount for the eye under examination. For example, the acquisition means may acquire the cylindrical correction amount and the astigmatism axis correction amount based on the refractive power (objective value) objectively measured of the eye under examination. Alternatively, for example, the acquisition means may acquire the cylindrical correction amount and the astigmatism axis correction amount based on the refractive power (subjective value) subjectively measured of the eye under examination. As an example, the subjective value of the eye under examination may be the corrected refractive power that is most positive in obtaining the best visual acuity of the eye under examination (full correction value), the corrected refractive power that obtains a predetermined visual acuity of the eye under examination (prescription value), etc. Of course, the acquisition means may acquire the spherical correction amount of the eye under examination along with the cylindrical refractive power and astigmatism axis angle of the eye under examination.

[0041] For example, the acquisition means may acquire the cylindrical correction amount and astigmatism axis correction amount input by the examiner through the operation of the operator's operation means (e.g., the examiner's controller 10). Alternatively, for example, the acquisition means may read an identifier for each subject and acquire the cylindrical correction amount and astigmatism axis correction amount stored in the identifier. As an example, the identifier may be an ID, a string, a one-dimensional code, a two-dimensional code, a color code, etc. Alternatively, for example, the acquisition means may acquire the cylindrical correction amount and astigmatism axis correction amount by receiving data measured using a device different from the subjective optometry device of this embodiment.

[0042] The subjective eye examination device of this embodiment may include an add power acquisition means (for example, a control unit 70). The add power acquisition means acquires the add power for the amount of correction at a predetermined examination distance of the eye being examined. For example, the add power may be a power based on at least one of the refractive power, accommodative power, age, etc., of the eye being examined.

[0043] For example, the add-in value acquisition means may acquire the add-in value entered by the operator operating the control means. Alternatively, for example, the add-in value acquisition means may read an identifier for each subject and acquire the add-in value stored in the identifier. Alternatively, for example, the add-in value acquisition means may acquire the add-in value by receiving data measured using a device different from the subjective ophthalmoscopic device of this embodiment.

[0044] The subjective optometry device of this embodiment may be equipped with control means. The same control means described in the section on "Changing the Spherical Refractive Power of the Target Light Beam" above can be used. Of course, it is also possible to provide different control means separately.

[0045] The control means may control the correction means in an add power test that measures the add power relative to the correction amount of the eye under test at a predetermined test distance. In other words, the control means may control the Stokes lens in an add power test. For example, the control means may change the composite axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction amount and astigmatism axis correction amount acquired by the acquisition means described above. For example, such a composite axis angle may be an axis angle that takes into account the amount of deviation in the astigmatism axis angle that occurs when assuming the arrangement of optical members and cross cylinder lenses to correct the eye under test by the cylindrical correction amount and astigmatism axis correction amount. The optical member here may be an optical member (for example, a cylindrical lens) that can adjust at least one of the cylindrical correction amount and astigmatism axis correction amount of the eye under test by changing at least one of the cylindrical refractive power and astigmatism axis angle of the target light beam. This allows the cylindrical refractive power and astigmatism axis angle of the target light beam to change seamlessly (without any gaps), reducing the discomfort caused by the switch in the cylindrical refractive power of the target light beam from the first modified cylindrical refractive power to the second modified cylindrical refractive power which is different from the first modified cylindrical refractive power (in other words, the amount of cylindrical correction of the eye being examined switches from the first amount of cylindrical correction to the second amount of cylindrical correction), and enabling accurate measurement of the refractive power of the eye being examined. Similarly, the discomfort caused by the switch in the astigmatism axis angle of the target light beam from the first modified astigmatism axis angle to the second modified astigmatism axis angle which is different from the first modified astigmatism axis angle (in other words, the amount of astigmatism axis correction of the eye being examined switches from the first amount of astigmatism axis correction to the second amount of astigmatism axis correction), enabling accurate measurement of the refractive power of the eye being examined.

[0046] The control means may correct the deviation in the spherical correction amount of the eye being examined by placing a corrective optical member in front of the eye being examined. In other words, the deviation in the spherical correction amount of the eye being examined may be corrected by placing a corrective optical member in the optical path of the target light beam and changing the spherical refractive power of the target light beam. For example, the control means may rotate the lens disc of the eye refractive power measurement unit to position a variable focal member on the lens disc as a corrective optical member in the examination window and change the focal length of the variable focal member. Alternatively, for example, the control means may rotate the lens disc of the eye refractive power measurement unit to position an optical member on the lens disc as a corrective optical member in the examination window. This ensures that the spherical correction amount of the eye being examined is appropriately corrected by the corrective optical member.

[0047] The control means may use a variable focal length member as a corrective optical member and correct the amount of deviation in the spherical correction amount of the eye under examination by changing the spherical refractive power of the variable focal length member. For example, since the amount of deviation in the spherical correction amount caused by the adjustment of the Stokes lens is small, the accuracy of the correction can be further improved by finely adjusting it using a variable focal length member.

[0048] The control means may set the composite axis angle using a table or calculation formula that associates the cylindrical correction amount and astigmatism axis correction amount of the eye under examination with the composite axis angle of the first cylindrical lens and the second cylindrical lens. Alternatively, the control means may arrange the corrective optical elements using a table or calculation formula that associates the cylindrical correction amount and astigmatism correction amount of the eye under examination with the amount of deviation in the astigmatism axis angle correction amount resulting from setting the composite axis angle of the first cylindrical lens and the second cylindrical lens. Of course, the control means may also perform the setting of the composite axis angle and the arrangement of the corrective optical elements using a table or calculation formula that associates the cylindrical correction amount and astigmatism axis correction amount of the eye under examination with the composite axis angle of the first cylindrical lens and the second cylindrical lens, and the amount of deviation in the astigmatism axis correction amount resulting from setting the composite axis angle. For example, such a table may be obtained in advance through experiments or simulations and stored in a memory means.

[0049] The control means may switch between a first state in which the first cylindrical lens and the second cylindrical lens are aligned to the combined axis angle, and a second state in which a corrective optical member based on the add power is further arranged in the first state. For example, the control means may switch from the first state to the second state by switching and arranging the corrective optical member in the optical path of the target light beam and changing the spherical refractive power of the target light beam. For example, the control means may rotate the lens disc of the eye refractive power measurement unit to arrange the variable focal member on the lens disc as a corrective optical member in the examination window, and change the focal length of the variable focal member. Alternatively, for example, the control means may rotate the lens disc of the eye refractive power measurement unit to arrange the optical member on the lens disc as a corrective optical member in the examination window. This ensures that the amount of spherical correction of the eye under examination is appropriately corrected by the corrective optical member. Since the deviation in the spherical correction amount of the eye being examined is corrected, and the system can switch between a state where no add power is applied to the eye and a state where add power is applied, the optimal add power for the eye can be measured with high accuracy.

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

[0051] <Examples> An embodiment of the subjective optometry device in this embodiment will be described. Figure 1 is an external view of the subjective optometry device 100. Figure 1(a) shows the ocular refractive power measurement unit 40 supported in the standby position. Figure 1(b) shows the ocular refractive power measurement unit 40 supported in the measurement position. For example, the subjective optometry device 100 includes a housing 1, a presentation window 2, a holding unit 4, an examiner controller 10, an ocular refractive power measurement unit 40, etc.

[0052] The housing 1 has a light projection optical system 30 inside. The presentation window 2 transmits the target light beam from the light projection optical system 30. The target light beam is projected onto the eye E being examined via the presentation window 2. If the refractive power measurement unit 40 is placed between the eye E being examined and the presentation window 2 (see Figure 1(b)), the target light beam is projected onto the eye E being examined via the presentation window 2 and the examination window 43 described later. In this way, the examination target is presented to the eye E being examined.

[0053] The holding unit 4 holds the eye refractive power measurement unit 40. For example, the holding unit 4 moves the eye refractive power measurement unit 40 connected to the arm by moving the arm driven by a drive unit (motor, etc.) not shown. This switches the eye refractive power measurement unit 40 between the standby position and the measurement position.

[0054] The examiner controller 10 is used by the examiner to operate the subjective ophthalmoscopic examination device 100. The examiner controller 10 includes a switch unit 11, a monitor 12, etc. The switch unit 11 receives signals for making various settings (for example, selecting a visual target to present to the subject, etc.). The monitor 12 displays various information (for example, the measurement result of the eye E being examined, etc.). The monitor 12 may also function as a touch panel that also serves as the switch unit 11. Signals from the examiner controller 10 are output to the control unit 60 via wired or wireless communication.

[0055] <Floodlight Optics> Figure 2 is a schematic diagram of the light projection optical system 30. Figure 2(a) shows the optical arrangement during distance vision testing. Figure 2(b) shows the optical arrangement during near vision testing. The light projection optical system 30 projects a target light beam toward the eye E under examination. For example, the light projection optical system 30 includes a display 31, a planar mirror 32, a concave mirror 33, a distance / near switching unit 34, etc.

[0056] The display 31 displays a visual target (e.g., a fixation target, a test target, etc.). The visual target is presented to the eye E when the light beam emitted from the display 31 forms an image on the fundus of the eye E being examined. For example, the display 31 may be an LCD (Liquid Crystal Display), an organic EL (Electro Luminescence), a plasma display, etc.

[0057] The planar mirror 32 reflects the target light beam from the display 31 and guides it to the concave mirror 33. The planar mirror 32 also reflects the target light beam from the display 31 and guides it to the eye under examination E. For example, during near vision testing of the eye under examination E, the planar mirror 32 is positioned so that the distance from the eye under examination E to the display 31 (presentation distance) is optically 40 cm. It is also possible to use reflective materials such as prisms, beam splitters, or half mirrors instead of the planar mirror 32.

[0058] The concave mirror 33 reflects the target light beam from the display 31 and guides it to the planar mirror 32. For example, the concave mirror 33 is positioned so that the distance from the eye E to the display 31 (presentation distance) is optically 5m during distance vision testing of the eye E. It is also possible to use reflective materials such as aspherical mirrors or free-form mirrors instead of the concave mirror 33. Furthermore, it is also possible to use lenses or the like instead of the concave mirror 33.

[0059] The distance / near switching unit 34 switches the arrangement of the display 31 during distance vision testing and near vision testing of the eye being examined E. For example, the distance / near switching unit 34 moves the display 31 held in the holder by moving the holder through the drive of a drive unit (motor, etc.) not shown. This switches the distance vision arrangement and near vision arrangement of the display 31.

[0060] For example, during distance vision testing of the eye under examination E, the display screen of the display 31 is directed towards the back of the housing 1 (see Figure 2(a)). The target light beam from the display 31 enters the planar mirror 32 through the optical axis L1 and is reflected by the planar mirror 32 in the direction of the optical axis L2. It also enters the concave mirror 33 through the optical axis L2 and is reflected by the concave mirror 33 in the direction of the optical axis L3. Furthermore, it enters the planar mirror 32 through the optical axis L3 and is reflected by the planar mirror 32 in the direction of the optical axis L4. As a result, the target light beam, which has passed through each optical component inside the housing 1 and is emitted to the outside of the housing 1, is projected onto the eye under examination E.

[0061] For example, during a near vision test of the eye under examination E, the display screen of the display 31 is directed towards the top surface of the housing 1 (see Figure 2(b)). The target light beam from the display 31 enters the plane mirror 32 passing through the optical axis L3 and is reflected by the plane mirror 32 in the direction of the optical axis L4. As a result, the target light beam, which has passed through each optical component inside the housing 1 and exited to the outside of the housing 1, is projected onto the eye under examination E.

[0062] <Ocular refractive power measurement unit (corrective optical system)> Figure 3 is a schematic diagram of the eye refractive power measurement unit 40. The eye refractive power measurement unit 40 subjectively measures the refractive power of the eye E being examined. The eye refractive power measurement unit 40 is also used as a corrective optical system. The corrective optical system is placed in the optical path of the light projection optical system 30 and changes the optical properties of the target light beam. For example, the eye refractive power measurement unit 40 includes a forehead rest 41, a lens unit 42, an examination window 43, a moving unit 44, etc.

[0063] The forehead rest 41 fixes the eye E to a predetermined examination position by pressing it against the subject's forehead, and maintains a constant distance from the eye E to the examination window 43. The lens unit 42 has a pair of left and right lens units 42L and 42R. The lens unit 42 has an examination window 43 (left examination window 43L and right examination window 43R).

[0064] The moving unit 44 adjusts the distance between the left lens unit 42L and the right lens unit 42R, and the convergence angle (inward angle) between the left lens unit 42L and the right lens unit 42R. For example, the moving unit 44 adjusts the distance between the left lens unit 42L and the right lens unit 42R by driving the drive unit 45 (left drive unit 45L and right drive unit 45R). Also, for example, the moving unit 44 adjusts the convergence angle between the left lens unit 42L and the right lens unit 42R by driving the drive unit 46. For detailed configuration of the moving unit 44, please refer to, for example, Japanese Patent Application Publication No. 2004-329345.

[0065] Figure 4 is a schematic diagram of the lens unit 42. Figure 4(a) is an internal configuration diagram of the lens unit 42. Figure 4(b) is a horizontal cross-sectional view of the lens unit 42. Note that Figures 4(a) and 4(b) show only the left lens unit 42L, and the right lens unit 42R is not shown. For example, the lens unit 42 includes a variable focus lens 61, a Stokes lens 62, and a lens disk 50.

[0066] The variable focus lens 61 is fixedly positioned within the lens unit 42. The variable focus lens 61 can generate a spherical refractive force that continuously changes within a predetermined range by adjusting the spherical refractive force according to the magnitude of the applied voltage and changing the focal position. For example, in this embodiment, a spherical refractive force of -5.00D to +5.00D can be generated.

[0067] The Stokes lens 62 is rotatably positioned within the lens unit 42. The Stokes lens 62 consists of two cylindrical lenses 62a and 62b. For example, the cylindrical lenses 62a and 62b are a positive cylindrical lens and a negative cylindrical lens with equal focal lengths. Alternatively, the cylindrical lenses 62a and 62b can be two positive cylindrical lenses with equal focal lengths.

[0068] The cylindrical lenses 62a and 62b are rotated independently around the optical axis L4 by the driving of the rotation mechanisms 63a and 63b, respectively. By changing the rotation angle of at least one of the cylindrical lenses 62a and 62b, and creating a difference in the axial angles of each cylindrical lens, a cylindrical refractive force that continuously changes within a predetermined range can be generated. For example, in this embodiment, a cylindrical refractive force of -10.00D to +10.00D can be generated. Furthermore, by changing the rotation angles of both cylindrical lenses 62a and 62b together while maintaining the difference in their axial angles (i.e., by changing the combined axial angle of cylindrical lenses 62a and 62b), the astigmatism axis angle that continuously changes within a predetermined range can be adjusted. For example, in this embodiment, the astigmatism axis angle can be adjusted from 1 degree to 180 degrees.

[0069] The lens disk 50 has an aperture (or a 0D lens) and multiple optical elements 51 on the same circumference. The lens disk 50 is rotated about the center of the disk by the drive unit 52. In addition, each optical element 51 is rotated about the optical axis L4 by the drive unit 53. As a result, the desired optical element 51 is switched and positioned in the inspection window 43 at the desired angle.

[0070] The lens disc 50 consists of one lens disc or multiple lens discs. For example, in this embodiment, a first auxiliary lens disc 50a and a second auxiliary lens disc 50b are provided. The first auxiliary lens disc 50a is provided with optical elements 51 such as a polarizing filter, a red filter / green filter, a dispersion prism, a Maddox lens, etc. The second auxiliary lens disc 50b is provided with optical elements 51 such as a clear lens, a rotary prism, an autocross cylinder lens, a first spherical lens 51a, a second spherical lens 51b, etc. For example, the clear lens is marked to align the interpupillary distance of the eye E under examination. For example, the first spherical lens 51a is a lens with a spherical power that corresponds to -10.00D when converted to the position of eyeglasses. For example, the second spherical lens 51b is a lens with a spherical power that corresponds to +10.00D when converted to the position of eyeglasses. For example, the spherical refractive powers of the first spherical lens 51a and the second spherical lens 51b are greater than a predetermined range of the spherical refractive power of the variable focus lens 61.

[0071] In this embodiment, the spectacle wearing position is the position assumed to be where the spectacle lenses are positioned in front of the eye E when the subject wears spectacles, and is the position of the optical element closest to the eye E (i.e., the variable focus lens 61). More specifically, it is the position G of the posterior surface of the variable focus lens 61. Furthermore, the distance from the corneal apex of the eye E to the position of the variable focus lens 61 (position G of the posterior surface of the variable focus lens 61) can be considered as the corneal apex distance VD.

[0072] <Adjustment range of spherical refractive power> In this embodiment, when the variable focus lens 61 is combined with either the first spherical lens 51a or the second spherical lens 51b, the range of spherical refractive power that can be adjusted by the variable focus lens 61 alone can be expanded. For example, by setting the variable focus lens 61 to any value from 0D to -5.00D and combining it with the first spherical lens 51a (-10.00D), a spherical refractive power of -10.00D to -15.00D can be generated. For example, by setting the variable focus lens 61 to any value from 0D to +5.00D and combining it with the second spherical lens 51b (+10.00D), a spherical refractive power of +10.00D to +15.00D can be generated.

[0073] In other words, in this embodiment, a spherical refractive power of -5.00D to +5.00D can be seamlessly generated using only a variable focus lens. Furthermore, by placing a first spherical lens 51a or a second spherical lens 51b in the inspection window 43 in addition to the variable focus lens 61, a spherical refractive power of -10.00D to -15.00D and a spherical refractive power of +10.00D to +15.00D can be seamlessly generated. Therefore, overall, a spherical refractive power of -15.00D to +15.00D can be seamlessly generated.

[0074] For example, the amount of spherical correction of the eye under examination E, the spherical refractive power of the variable focus lens 61, and the spherical refractive powers of the first spherical lens 51a and the second spherical lens 51b may be pre-associated. For example, if the amount of spherical correction of the eye under examination E exceeds the spherical refractive power that can be adjusted by the variable focus lens 61, the first spherical lens 51a and the second spherical lens 51b may be pre-associated to generate spherical refractive power (in other words, to position the first spherical lens 51a or the second spherical lens 51b). As an example, a reference table or the like may be prepared in advance and stored in memory 75 to refer to the value of the spherical refractive power of the variable focus lens 61 and the value of the spherical refractive powers of the first spherical lens 51a and the second spherical lens 51b based on the amount of spherical correction of the eye under examination E.

[0075] <Reproduction of the arrangement of cross cylinder lenses> Here, we will briefly explain the lens unit included in a conventional refractive power measurement unit. Figure 5 is a schematic diagram of a conventional lens unit 200. Figure 5(a) is an internal configuration diagram of the conventional lens unit 200. Figure 5(b) is a horizontal cross-sectional view of the conventional lens unit 200. Note that Figures 5(a) and 5(b) show only the left lens unit, and the right lens unit is not shown.

[0076] The lens unit 200 comprises multiple lens discs 210. For example, a strong spherical lens disc 210a, a weak spherical lens disc 210b, a strong cylindrical lens disc 210c, a weak cylindrical lens disc 210d, a first auxiliary lens disc 210e, and a second auxiliary lens disc 210f are provided in the direction away from the eye E under examination. Spherical lenses ranging from -18.00D to +15.00D are provided on the strong spherical lens disc 210a at 3.00D intervals. Spherical lenses ranging from -1.00D to +1.75D are provided on the weak spherical lens disc 210b at 0.25D intervals. Cylindrical lenses ranging from -1.50D to -7.50D (calculated for eyeglass wearing position) are provided on the strong cylindrical lens disc 210c at 1.50D intervals. The weak cylindrical lens disc 210d is provided with cylindrical lenses ranging from -0.25D to -1.25D in terms of eyeglass wearing position, at 0.25D intervals. The first auxiliary lens disc 210e is provided with a polarizing filter, red filter / green filter, dispersion prism, Maddox lens, etc. The second auxiliary lens disc 210f is provided with a clear lens, rotary prism, auto-cross cylinder lens, cross cylinder lens, etc. For details of the lens unit 200, please refer to, for example, Japanese Patent Publication No. 2007-125125.

[0077] Conventional lens units 200 are provided with a strong cylindrical lens disc 210c, a weak cylindrical lens disc 210d, and a cross-cylinder lens. For example, a cross-cylinder lens is a lens formed by combining cylindrical lenses with opposite and equal cylindrical refractive powers such that their astigmatism axis angles are orthogonal. One example is a lens formed by combining cylindrical lenses with -0.25D and +0.25D so that their astigmatism axis angles are orthogonal. On the other hand, the lens unit 42 of this embodiment has a Stokes lens 62 (cylindrical lens 62a and cylindrical lens 62b) instead of the strong cylindrical lens disc 210c and weak cylindrical lens disc 210d, and does not have a cross-cylinder lens.

[0078] Figure 6 shows the change in the combined refractive power of the cylindrical lens and the cross-cylinder lens in the cylindrical lens disc in a conventional lens unit 200. For example, a cylindrical lens 250 of a weak cylindrical lens disc 210d is switched and placed in front of the eye of the eye being examined E. As an example, the cylindrical lens 250 is a lens with a cylindrical refractive power of -1.00D and is rotated so that its astigmatism axis angle is 135 degrees. At this time, the refractive power of the cylindrical lens 250 changes in a sine curve α that passes through -0.50D at 0 degrees, 90 degrees, and 180 degrees, -1.00D at 45 degrees, and 0.00D at 135 degrees.

[0079] Furthermore, for example, the cross-cylinder lens 260 of the first auxiliary lens disk 210e is switched and positioned in front of the eye E under examination. As an example, the cross-cylinder lens 260 is rotated so that +0.25D is 90 degrees. At this time, the refractive power of the cross-cylinder lens 260 changes in a sine curve β that passes through -0.25D at 0 degrees and 180 degrees, 0.00D at 45 degrees and 135 degrees, and +0.25D at 90 degrees.

[0080] For example, when both a cylindrical lens 250 and a cross-cylinder lens 260 are switched and placed in front of the eye E under examination, a combined refractive power is generated by combining the refractive powers of each. In this case, the combined refractive power changes along a sine curve γ that passes through -0.75D, -1.00D, -0.25D, 0.00D, and -0.75D in the order of 0 degrees, 45 degrees, 90 degrees, 135 degrees, and 180 degrees. For example, the sine curve α of the refractive power of the cylindrical lens 250 has its peak at 135 degrees, while the sine curve γ of the combined refractive power of the cylindrical lens 250 and the cross-cylinder lens 260 has its peak shifted to 122 degrees.

[0081] In this embodiment, by considering the amount of astigmatism axis angle shift that occurs when arranging the cylindrical lens 250 and the cross-cylinder lens 260, and setting the combined axis angle of the cylindrical lens 62a and the cylindrical lens 62b in the Stokes lens 62, the arrangement of the cylindrical lens 250 and the cross-cylinder lens 260 can be created using only the Stokes lens 62. For example, the aforementioned arrangement of the cylindrical lens 250 and the cross-cylinder lens 260 can be reproduced by adjusting the difference in axis angles between the cylindrical lens 62a and the cylindrical lens 62b to a difference that generates a cylindrical refractive force of -1.00D, and by arranging the combined axis angle of the cylindrical lens 62a and the cylindrical lens 62b to a position of 122 degrees instead of 135 degrees.

[0082] For example, the cylindrical correction amount and astigmatism axis angle of the eye under examination E may be pre-associated with the combined axis angle of the cylindrical lens 62a and cylindrical lens 62b. As an example, a reference table may be prepared in advance and stored in memory 75 to refer to the values ​​of the astigmatism axis angles of the cylindrical lens 62a and cylindrical lens 62b based on the cylindrical correction amount and astigmatism axis correction amount of the eye under examination E.

[0083] In the conventional lens unit 200, when a spherical lens, a cylindrical lens 250, and a cross-cylinder lens 260 are placed in front of the eye E under examination, the equivalent spherical value of the eye E under examination is taken into consideration. For example, when the cylindrical lens 250 is switched to change the cylindrical refractive power by 0.25D (1 step), a spherical refractive power of 0.125D is generated. For example, if the spherical lenses are provided at 0.25D intervals, when the cylindrical refractive power is changed by 0.50D (2 steps), the spherical lens can be switched to change the spherical refractive power by 0.25D, and a correction considering the equivalent spherical value is performed. In this embodiment, by using the variable focus lens 61, it is possible to easily perform a correction that takes into account the change in spherical refractive power accompanying the change in cylindrical refractive power. Furthermore, when the cylindrical refractive power is finely changed by the Stokes lens 62, the spherical refractive power changes in various ways, but even in such cases, a correction can be easily performed.

[0084] <Department Head> Figure 7 is a schematic diagram of the control system of the subjective optometry device 100. For example, the control unit 70 includes a CPU (processor), RAM, ROM, etc. The CPU controls the operation of each part of the subjective optometry device 100. Various types of information are temporarily stored in the RAM. Various programs executed by the CPU are stored in the ROM. Note that the control unit 70 may be composed of multiple control units (i.e., multiple processors).

[0085] The control unit 70 is connected to the display 31, the examiner controller 10, the non-volatile memory 75 (hereinafter referred to as memory 75), etc. The control unit 70 is also connected to the drive unit of the holding unit 4, the drive unit of the near / far switching unit 34, the drive unit of the refractive power measurement unit 40 (drive units 45, 46, 52, 53), etc.

[0086] Memory 75 is a non-transient storage medium that can retain its contents even when the power supply is cut off. For example, memory 75 may be a hard disk drive, flash ROM, USB memory, etc.

[0087] <Control operation> The control operation of the subjective optometry device 100 will be explained.

[0088] The examiner adjusts the position of the forehead rest 170 by operating a forehead rest adjustment knob (not shown) so that the corneal vertex distance VD of the eye under examination E is a predetermined distance (for example, 12 mm). The examiner also inputs the interpupillary distance of the eye under examination by operating the examiner controller 10. The control unit 70 adjusts the spacing of the lens units 42 to align the examination window 43 with the interpupillary distance.

[0089] <Setting the initial correction amount> The examiner operates the examiner controller 10 to input the objective refractive power (objective value) of the eye under examination E, which was previously obtained through objective measurement, as the initial correction amount for the eye under examination E. That is, the initial spherical correction amount, the initial cylindrical correction amount, and the initial astigmatism axis correction amount are input. The control unit 70 applies a voltage to the variable focus lens 61 and rotates the Stokes lens 62 and the lens disk 50 based on the aforementioned reference table. The control of the variable focus lens 61, the Stokes lens 62, and the lens disk 50 may be performed sequentially or almost simultaneously.

[0090] In this embodiment, we take the case where the objective refractive power (objective value) of the eye E under examination is -6.50D for the spherical eye, -1.00D for the cylindrical eye, and 135 degrees for the astigmatism axis angle. In this case, the initial correction amount for the eye E under examination may be -6.50D for the spherical correction, -1.00D for the cylindrical correction, and 135 degrees for the astigmatism axis correction. For example, the control unit 70 adjusts the spherical refractive power of the variable focus lens 61 to +3.50D. Alternatively, for example, the control unit 70 changes the difference in axial angles between the cylindrical lenses 62a and 62b to adjust the cylindrical refractive power to -1.00D. Alternatively, for example, the control unit 70 adjusts the combined axial angle of the cylindrical lenses 62a and 62b to 135 degrees. Furthermore, for example, the control unit 70 places the opening of the first auxiliary lens disk 50a and the first spherical lens 51a (spherical refractive power -10.00D) of the second auxiliary lens disk 50b in the inspection window 43.

[0091] This corrects the target light beam from the display 31 to focus onto the retina of the eye E being examined. In other words, the eye E being examined is corrected with a spherical correction amount of -6.50, which is the sum of the variable focus lens 61 and the first spherical lens 51a. In addition, the eye E being examined is corrected with a cylindrical correction amount of -1.0D and an astigmatism axis correction amount of 135 degrees by the Stokes lens 62.

[0092] <Distance vision test> After correcting the eye E to the initial correction amount, the examiner operates the examiner controller 10 to start a distance visual acuity test at a predetermined distance (in this case, the distance test distance) of the eye E. The control unit 70 switches and positions the display 31 for distance vision. The control unit 70 also displays a Landolt ring target with a predetermined visual acuity value on the display 31 as the initial target. As an example, a Landolt ring target with a visual acuity value of 0.8 is displayed as the initial target.

[0093] The examiner operates the examiner controller 10 to switch between Landolt ring targets and ask the subject about the direction of the gap in the Landolt ring target. For example, if the subject's answer is correct, the visual acuity value of the Landolt ring target is switched to one step higher. That is, the increment of the visual acuity value of the Landolt ring target is increased by one, switching to a value larger than the current value. As an example, the visual acuity value of the Landolt ring target is switched from 0.8 to 0.9. For example, if the subject's answer is incorrect, the visual acuity value of the Landolt ring target is switched to one step lower. That is, the increment of the visual acuity value of the Landolt ring target is decreased by one, switching to a value smaller than the current value. As an example, the visual acuity value of the Landolt ring target is switched from 0.8 to 0.7. The examiner repeats these steps to find the highest visual acuity value of the Landolt ring target that the subject's eye E can read.

[0094] Next, the examiner operates the examiner controller 10 to switch the correction amount for the eye E under examination while asking the subject about the direction of the gap in the Landolt ring target. For example, if the subject's answer is correct, the spherical correction amount is switched to one step weaker. That is, the spherical correction amount is decreased by one step and switched to a value smaller than the current value. As an example, by changing the spherical refractive power of the variable focus lens 61 from +3.50D to +3.25D, the spherical correction amount correcting the eye E under examination is switched from -6.50D to -6.25D. For example, if the subject's answer is incorrect, the spherical correction amount is switched to one step stronger. That is, the spherical correction amount is increased by one step and switched to a value larger than the current value. For example, by changing the spherical refractive power of the variable focus lens 61 from +3.50D to +3.75D, the amount of spherical correction can be switched from -6.50D to -6.75D.

[0095] The control unit 70 positions the first spherical lens 51a or the second spherical lens 51b as needed, according to the amount of spherical correction to be applied to the eye E under examination. Of course, the amount of cylindrical correction and the amount of astigmatism axis correction may be switched along with the amount of spherical correction, depending on the subject's response. In this embodiment, the variable focus lens 61 makes it possible to change the amount of spherical correction in steps finer than -0.25D. Similarly, the cylindrical lenses 62a and 62b of the Stokes lens 62 make it possible to change the amount of cylindrical correction in steps finer than -0.25D. The examiner repeats these steps to determine the value of the corrected refractive power that is closest to positive (i.e., the full correction value) that yields the best visual acuity of the eye E under examination.

[0096] <Membership Inspection> After completing the distance visual acuity test of the eye E under examination, the examiner operates the examiner controller 10 to start the add power test with the eye E corrected to its full correction value at a predetermined distance (distance test distance). For example, the examiner determines the need for add power and sets the initial add power based on at least one of the following: the age of the subject, the accommodative power of the eye E, the refractive power of the eye E, etc. Of course, the control unit 70 may automatically determine and set the need for add power and the initial add power.

[0097] In this embodiment, we take the case where the fully corrected value (subjective value) of the eye E under examination is determined to be a spherical correction amount of -6.00D, a cylindrical correction amount of -1.25D, and an astigmatism axis correction amount of 135 degrees, and the initial add power is set to +1.00D. In conventional add power testing using lens unit 200, the eye E under examination is corrected to its fully corrected value, and a cross cylinder lens is positioned so that -0.50D is 0 degrees and +0.50D is 90 degrees, and the initial add power is increased or decreased. In this embodiment, the state in which the eye E under examination is corrected to its fully corrected value and a cross cylinder lens is positioned is reproduced using a Stokes lens 62, and then the initial add power is increased or decreased.

[0098] First, the control unit 70 creates a first state in which the eye E under examination is corrected to its full correction value and a cross-cylinder lens is positioned. The control unit 70 assumes that the cylindrical lens 250 of the conventional lens unit 200 has a cylindrical refractive power of -1.25D and is positioned at 135 degrees, and that the cross-cylinder lens 270 has a refractive power of +0.50D and is positioned at 90 degrees. The control unit 70 rotates the cylindrical lenses 62a and 62b of the Stokes lens 62 to correct the cylindrical correction amount of the eye under examination E to -1.25D and the astigmatism axis angle to 135 degrees.

[0099] Figure 8 shows the change in the combined refractive power of the cylindrical lens 250 and the cross-cylinder lens 270. The refractive power of the cylindrical lens 250 changes along a sine curve α that passes through -1.25D at 45 degrees, and the refractive power of the cross-cylinder lens 270 changes along a sine curve β that passes through +0.50D at 90 degrees. The sine curve γ of the combined refractive power of the cylindrical lens 250 and the cross-cylinder lens 270 has its peak at 116 degrees. Therefore, the control unit 70 adjusts the difference in axial angles between the cylindrical lens 62a and the cylindrical lens 62b of the Stokes lens 62 to a difference that generates a cylindrical refractive power of -1.25D, and positions the combined axial angle of the cylindrical lens 62a and the cylindrical lens 62b at 116 degrees instead of 135 degrees. This corrects the eye E under examination by reproducing a state where the cylindrical correction amount (CYL) is -1.25D, the astigmatism axis correction amount (AXIS) is 135 degrees, and a cross-cylinder lens 270 (+0.50D in the 90-degree direction) is combined.

[0100] At this time, a spherical refractive power ΔS is generated due to the difference between the amount of astigmatism axis correction of the eye E being examined and the combined axis angle of the cylindrical lens 62a and the cylindrical lens 62b. The spherical refractive power ΔS is a quantity that appears as the difference in refractive power between the refractive power of the cylindrical lens 250 and the combined refractive power of the cylindrical lens 250 and the cross-cylinder lens 260 (in Figure 8, the difference on the vertical axis at the peaks of the sine curve α and the sine curve γ). Note that the spherical refractive power ΔS changes according to the difference between the amount of astigmatism axis correction and the combined axis angle, but it is a small amount, less than one step (0.25D). For example, in this embodiment, the spherical refractive power ΔS is -0.15D.

[0101] The control unit 70 changes the spherical refractive power of the variable focus lens 61 to +4.00D and switches the position of the first spherical lens 51a (-10.00D) to correct the eye E under examination with a spherical correction amount of -6.00D. However, because a spherical refractive power ΔS is generated by the Stokes lens 62, in reality, the spherical refractive power of the variable focus lens 61 is set to +3.85D, and the eye E under examination is corrected with a spherical correction amount of -6.15D. For example, by using the variable focus lens 61 in this way, the numerical values ​​can be finely adjusted taking into account the spherical refractive power ΔS.

[0102] The examiner operates the examiner controller 10 to display the cross grid target on the display 31. The examiner also operates the examiner controller 10 to press a switch (not shown) to switch between a first state, which assumes that the eye E under examination is corrected to the full correction value and a cross cylinder lens is placed, and a second state, which is the first state with an additional initial add power of +1.00D. The control unit 70 changes the spherical refractive power of the variable focus lens 61 in response to the operation signal from the switch (not shown). Here, the spherical refractive power of the variable focus lens 61 is changed to +3.85D or +4.85D. As a result, the amount of spherical correction of the eye under examination E is switched between -6.00D (actually -6.15D) without the initial add power and -5.00D (actually -5.15D) with the initial add power added.

[0103] The examiner asks the subject how they see the cross grid target and changes the add power according to the subject's response. The control unit 70 changes the spherical refractive power of the variable focus lens 61 in accordance with the spherical refractive power added to the subject's eye E, and positions the first spherical lens 51a or the second spherical lens 51b as needed. The examiner repeats these steps and determines the appropriate add power for the subject's eye E when the vertical and horizontal lines of the cross grid target appear equally clear.

[0104] <Near-vision vision test> After completing the add power test of the eye E under examination, the examiner operates the examiner controller 10 to start the near vision test at a predetermined distance (in this case, the near vision test distance) of the eye E under examination. The control unit 70 switches the display 31 to the near vision position. In conventional lens units 200, the cross cylinder lens 270 is removed when transitioning from the add power test to the near vision test. Therefore, in this embodiment as well, the variable focus lens 61 and Stokes lens 62 (cylindrical lens 62a and cylindrical lens 62b) are adjusted to reproduce the state with the cross cylinder lens 270 removed. The highest visual acuity value is also required in the near vision test, but this procedure is basically the same as in the distance vision test and is therefore omitted.

[0105] As explained above, for example, the subjective optometry device of this embodiment controls a first correction means for changing the spherical refractive power of the target light beam using a variable focal length variable focal member (here, a variable focal lens 61), and a second correction means for changing the spherical refractive power of the target light beam by switching and arranging optical members (here, a first spherical lens 51a and a second spherical lens 51b), thereby changing the spherical refractive power of the target light beam. For example, the variable focal member can continuously change the spherical refractive power, and for this reason, the amount of spherical correction of the eye under examination can be finely adjusted to appropriately correct the eye under examination. However, on the other hand, it is technically difficult for the variable focal member to generate high-level spherical refractive power, and changes in spherical refractive power by the variable focal member alone may not be able to cope when the amount of spherical correction of the eye under examination is large. In this embodiment, by combining the variable focal lens with the first spherical lens or the second spherical lens as needed, it becomes possible to generate high-level spherical refractive power. Therefore, even when the amount of spherical correction required for the eye under examination is large, the eye under examination can be appropriately corrected, and its refractive power can be measured accurately.

[0106] For example, conventionally, when a spherical lens was switched in front of the eye being examined, the sudden change from one spherical refractive power to another (in other words, a seam in the spherical refractive power) could cause discomfort, or the sound of the spherical lens switching could be bothersome. In this embodiment, by adjusting the desired spherical refractive power using a variable focus member, the spherical refractive power changes seamlessly (without seams), allowing the measurement to proceed without discomfort. Furthermore, since no sound is generated when the spherical lens is switched, bothersomeness can be reduced.

[0107] Furthermore, for example, in the subjective optometry device of this embodiment, the first corrective means is capable of changing the spherical refractive power of the target light beam within the range of the first refractive power, and when the modified spherical refractive power, which is the changed spherical refractive power of the target light beam, exceeds the range of the first refractive power of the spherical refractive power in the first corrective means, at least the optical member is switched and positioned. For example, when the variable focus member is positioned in front of the eye under examination, the spherical refractive power can be continuously changed within the range of the first refractive power, and the subjective examination of the eye under examination can proceed smoothly. Also, for example, when the variable focus member and optical member are positioned in front of the eye under examination, the spherical refractive power (composite spherical refractive power) can be amplified by the optical member, and the composite spherical refractive power can be continuously changed by the variable focus member, and the subjective examination of the eye under examination can proceed smoothly.

[0108] Furthermore, for example, in the subjective optometry device of this embodiment, the step in which the first corrective means can change the spherical refractive power of the target light beam is smaller than the step in which the second corrective means can change the spherical refractive power of the target light beam. This allows for finer adjustment of the spherical refractive power of the target light beam using a variable focus member. Moreover, even when a variable focus member and an optical member are combined, the spherical refractive power of the target light beam can be finer adjusted within the range of their combined spherical refractive power.

[0109] Furthermore, for example, in an add power test that measures the add power relative to the correction amount at a predetermined examination distance of the eye being examined, the subjective optometry device of this embodiment controls a Stokes lens that can be independently rotated in front of the eye being examined, and changes the combined axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction amount and astigmatism axis correction amount of the eye being examined. Here, the combined axis angle is an axis angle that takes into account the amount of deviation in the astigmatism axis correction amount that occurs when assuming the arrangement of optical members and cross cylinder lenses to correct the eye being examined with the cylindrical correction amount and astigmatism axis correction amount. For example, with the Stokes lens placed in front of the eye being examined, it is possible to continuously change the cylindrical refractive power by adjusting the difference in axis angles by rotating the two cylindrical lenses individually, and it is possible to continuously change the astigmatism axis angle by adjusting the combined axis angle by rotating the two cylindrical lenses together. In this embodiment, the amount of deviation in the astigmatism axis correction amount caused by the Stokes lens is taken into consideration, so the cylindrical correction amount and astigmatism axis correction amount of the eye under examination can be appropriately corrected, and the refractive power of the eye under examination can be measured with accuracy.

[0110] For example, conventionally, when a cylindrical lens was switched in front of the eye being examined, there was discomfort due to the abrupt change in the cylindrical refractive power, similar to when a spherical lens was switched as described above, as well as annoyance from the sound of the cylindrical lens being switched. However, in this embodiment, by adjusting the desired cylindrical refractive power using a Stokes lens, the cylindrical refractive power changes seamlessly (without a seam), and no switching sound is generated, thus reducing discomfort and annoyance.

[0111] Furthermore, for example, the subjective optometry device of this embodiment corrects the deviation in the spherical correction amount of the eye being examined, which occurs when the first cylindrical lens and the second cylindrical lens are aligned to the combined axis angle, by placing a corrective optical element in front of the eye being examined. As a result, even when the cylindrical refractive power and astigmatism axis angle of the target light beam are changed using a Stokes lens to adjust the cylindrical correction amount and astigmatism axis correction amount of the eye being examined, the deviation in the spherical correction amount of the eye being examined is appropriately corrected by the corrective optical element, allowing for accurate measurement of the refractive power of the eye being examined.

[0112] Furthermore, for example, in the subjective optometry device of this embodiment, the corrective optical member for correcting the deviation in the amount of spherical correction of the eye under examination is a variable focal length member (here, a variable focal lens 61), and the deviation in the amount of spherical correction of the eye under examination is corrected by changing the spherical refractive power of the variable focal member. For example, the deviation in the amount of spherical correction generated by the first cylindrical lens and the second cylindrical lens can change by a value smaller than the spacing (0.25D) between the multiple spherical lenses that make up a conventional lens unit. For this reason, if a spherical optical member with a constant focal length is used as the corrective optical member, it may not be able to adequately respond to the deviation in the amount of spherical correction, but by using a variable focal length member, it becomes possible to respond more precisely to the deviation in the amount of spherical correction. As a result, the eye under examination can be appropriately corrected to the desired amount of spherical correction.

[0113] Furthermore, for example, the subjective optometry device of this embodiment acquires the add power of the eye under examination and switches between a first state in which the first cylindrical lens and the second cylindrical lens are aligned to the combined axis angle, and a second state in which a corrective optical element based on the add power is positioned in the first state. That is, the eye under examination is corrected with a predetermined amount of spherical correction, cylindrical correction, and astigmatism axis correction, and the deviation of the spherical correction amount is further corrected, and then the device switches between the first state without add power and the second state with add power. This makes it possible to accurately measure the optimal add power for the eye under examination.

[0114] Furthermore, for example, the subjective optometry device of this embodiment combines a corrective optical member for correcting the deviation in the spherical correction amount of the eye being examined and a corrective optical member for correcting the eye being examined with the spherical correction amount. This makes it possible to easily adjust the amount of spherical correction to correct the eye being examined, taking into account the deviation in the spherical correction amount of the eye being examined.

[0115] <Example of transformation> The subjective optometry device of this embodiment has been described using a configuration in which the spherical refractive power is adjusted in steps of 0.25D as an example, but is not limited to this. For example, the subjective optometry device of this embodiment can continuously change the spherical refractive power of the variable focus lens 61. For this reason, the spherical refractive power may be adjusted in steps smaller than 0.25D (e.g., 0.10D, 0.05D, etc.). Similarly, the subjective optometry device of this embodiment has been described using a configuration in which the cylindrical refractive power is adjusted in steps of 0.25D as an example, but is not limited to this. For example, the subjective optometry device of this embodiment can continuously change the cylindrical refractive power of the Stokes lens 62. For this reason, the cylindrical refractive power may be adjusted in steps smaller than 0.25D (e.g., 0.10D, 0.05D, etc.).

[0116] The subjective optometry device of this embodiment has been described using a configuration in which the amount of spherical correction of the eye under examination E, the spherical refractive power of the variable focus lens 61, and the arrangement of the first spherical lens 51a and the second spherical lens 51b are pre-associated, but it is not limited to this configuration. For example, the subjective optometry device of this embodiment may be configured to determine whether or not to arrange the first spherical lens 51a and the second spherical lens 51b based on the amount of spherical correction of the eye under examination E. In this case, the control unit 70 may determine whether or not to arrange the first spherical lens 51a and the second spherical lens 51b based on whether or not the amount of spherical correction of the eye under examination E exceeds a predetermined threshold. For example, the predetermined threshold may be the maximum or minimum value based on the range of spherical refractive power that can be adjusted by the variable focus lens 61.

[0117] Thus, the subjective optometry device of this embodiment determines whether or not to place optical elements (here, the first spherical lens 51a and the second spherical lens 51b) in front of the eye E of the eye being examined, based on the amount of spherical correction of the eye being examined (i.e., the modified spherical refractive power obtained by changing the spherical refractive power of the target light beam), and based on the determination result, switches and places at least the optical elements. This makes it easy to identify, for example, when the amount of spherical correction of the eye being examined is large and cannot be addressed by simply adjusting the spherical refractive power of the variable focus member (here, the variable focus lens 61), and to combine the variable focus member and optical elements to accurately measure the refractive power of the eye being examined.

[0118] Furthermore, for example, the subjective optometry device of this embodiment determines whether or not to place an optical element in front of the eye being examined based on the amount of spherical correction of the eye being examined (the spherical refractive power of the modified target light beam) and the range of refractive power in the correction means. This allows for accurate measurement of the refractive power of the eye being examined by appropriately positioning the optical element when the variable optical element alone is insufficient.

[0119] In the subjective optometry device of this embodiment, in the aforementioned distance visual acuity test and near visual acuity test, the initial correction amount of the eye E being examined, or the correction amount switched to after the initial correction amount, may be changed to a different correction amount. In this case, the control unit 70 may change whether to control only the variable focus member 61 or to control both the variable focus member 61 and the first spherical lens 51a (or the second spherical lens 51b) depending on the amount of change of the two correction amounts. For example, if the amount of change of the two correction amounts does not exceed a predetermined amount, the control unit 70 may control only the variable focus member 61. Alternatively, if the amount of change of the two correction amounts exceeds a predetermined amount, the control unit 70 may control both the variable focus member 61 and the first spherical lens 51a (or the second spherical lens 51b). For example, the amount of change of the two correction amounts may be set in advance, for example, ±3.00D.

[0120] Thus, in this embodiment, when adjusting the amount of spherical correction of the eye under examination (the modified spherical refractive power obtained by changing the spherical refractive power of the target light beam) from a first modified spherical refractive power to a second modified spherical refractive power different from the first modified spherical refractive power, the subjective optometry device of this embodiment controls only the first correction means and changes the focal length of the variable focal member according to the amount of change between the first modified spherical refractive power and the second modified spherical refractive power. This makes it possible to easily adjust the amount of spherical correction required for correcting the eye under examination and to smoothly measure the refractive power of the eye under examination.

[0121] In the subjective optometry device of this embodiment, after switching from the initial correction amount to a different correction amount for the eye under examination E, the device may be configured to determine the subjective value (e.g., the full correction value) by controlling only the variable focus member 61. In this case, it may be set in advance whether or not to place the first spherical lens 51a or the second spherical lens 51b in the examination window 43, depending on the initial correction amount of the eye under examination E. For example, if the initial correction amount of the eye under examination E is a spherical correction amount of -1.00D, -1.00D may be generated using only the variable focus member 61 (spherical refractive power -5.00D to +5.00D). Alternatively, for example, if the initial correction amount of the eye under examination E is a spherical correction amount of -4.50D, -4.5D may be generated by combining the variable focus member 61 and the first spherical lens 51a (spherical refractive power -10.00D). For example, the amount of change in the initial correction amount of the eye E being examined until it is adjusted to the final correction amount (i.e., the difference between the initial and final correction amounts) can be roughly determined from experiments or simulations. Therefore, by pre-positioning the first spherical lens 51a according to the initial correction amount of the eye E being examined, it becomes unnecessary to rotate the second auxiliary lens disc 50b during the measurement of the eye E being examined, enabling a more seamless response. In such a configuration, multiple spherical lenses may be provided, and their spherical refractive power may be changed in predetermined steps (for example, in units of 3.00D). [Explanation of symbols]

[0122] 1 cabinet 2. Presentation window 10. Examiner's Controller 30 Floodlight Optics 40. Refractive power measurement unit 43 Inspection window 60 Control Unit 100 Self-aware eye examination device

Claims

1. A subjective ophthalmoscopic device for subjectively measuring the refractive power of the eye being examined, A corrective means is placed in front of the eye under examination and changes the optical properties of the target light beam emitted from the target presentation means, An acquisition means for acquiring at least the cylindrical correction amount and the astigmatism axis correction amount for the eye under examination, Control means for controlling the corrective means, Equipped with, The corrective means includes a Stokes lens comprising a first cylindrical lens and a second cylindrical lens that are independently rotatable in front of the eye. The control means controls the Stokes lens in an add power test that measures the add power relative to the correction amount at a predetermined test distance of the eye under test, and changes the combined axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction amount and the astigmatism axis correction amount. The subjective eye examination device is characterized in that the composite axis angle is an axis angle that takes into account the amount of deviation in the astigmatism axis correction amount that occurs when assuming the arrangement of optical members and cross cylinder lenses in order to correct the eye to be examined by the cylindrical correction amount and the astigmatism axis correction amount.

2. In the subjective eye examination device of claim 1, The acquisition means acquires the amount of spherical correction of the eye under examination, The corrective means includes a corrective optical member for correcting the amount of deviation in the spherical correction amount of the eye under examination, which occurs when the first cylindrical lens and the second cylindrical lens are aligned to the composite axis angle. The control means is characterized by correcting the amount of deviation of the spherical correction amount by placing the corrective optical member in front of the eye.

3. In the subjective eye examination device of claim 2, The corrective optical member is a variable focal length member, The control means is characterized by correcting the amount of deviation of the spherical correction amount of the eye being examined by changing the spherical refractive power of the variable focal member.

4. In the subjective ophthalmoscopic device according to either claim 2 or 3, The system includes means for obtaining the addition power of the eye to be examined, The corrective means includes a corrective optical member for correcting the amount of spherical correction of the eye under examination, The control means is characterized by switching between a first state in which the first cylindrical lens and the second cylindrical lens are aligned to the composite axis angle, and a second state in which the corrective optical member based on the addition degree is positioned in the first state.

5. A corrective means positioned in front of the eye under examination and for altering the optical properties of a target light beam emitted from a target presentation means, comprising a Stokes lens including a first cylindrical lens and a second cylindrical lens that are independently rotatable in front of the eye, A subjective optometry program used in a subjective optometry device for subjectively measuring the refractive power of the eye under examination, This is executed by the processor of the aforementioned subjective optometry device, An acquisition step to obtain at least the cylindrical correction amount and the astigmatism axis correction amount of the eye under examination, A control step for controlling the corrective means, The subjective optometry device is made to perform the following: The control step, in an add power test that measures the add power relative to the correction amount of the eye under test at a predetermined test distance, controls the Stokes lens and changes the combined axis angle of the first cylindrical lens and the second cylindrical lens to a predetermined axis angle based on the cylindrical correction amount and the astigmatism axis correction amount. A subjective eye examination program characterized in that the composite axis angle is an axis angle that takes into account the amount of deviation in the astigmatism axis correction amount that occurs when assuming the arrangement of optical members and cross-cylinder lenses in order to correct the eye under examination by the cylindrical correction amount and the astigmatism axis correction amount.

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