Subjective optometry device and subjective optometry program

Abstract

Provided is a subjective optometry device for subjectively measuring the eye refractive power of an eye being examined, wherein the subjective optometry device comprises: a correction means which is disposed in front of the eye being examined, and changes optical characteristics of visual target luminous flux emitted from a visual target presentation means; and a control means which controls the correction means, wherein the correction means includes a first correction means for using a variable focusing member of which the focal length is variable and changing the spherical refractive power of the visual target luminous flux, and a second correction means for switching optical members and changing the spherical refractive power of the visual target luminous flux, and the control means controls the first correction means and the second correction means and changes the spherical refractive power of the visual target luminous flux.

Description

Subjective optometry device and subjective optometry program

[0001] The present disclosure relates to a subjective optometry device and a subjective optometry program for subjectively measuring the ocular refractive power of a subject's eye.

[0002] There is known a subjective optometry device that measures the ocular refractive power of a subject's eye by placing an optical element in front of the subject's eye and presenting a test target through the optical element to the subject's eye. In Patent Document 1, a variable-focus lens capable of changing the focal length is used as the optical element to change the spherical refractive power of the target light beam, thereby changing the amount of spherical correction used to correct the subject's eye.

[0003] Special table 2017-510384 publication

[0004] For example, the above-mentioned subjective ophthalmology device can seamlessly (without seams) change the spherical correction of the subject's eye from one correction amount to another within the range (variable range) in which the spherical refractive power of the visual target light beam can be changed by the variable-focus lens. However, since it is technically difficult for a variable-focus lens to significantly change the focal length (i.e., to change the spherical refractive power of the visual target light beam in terms of the degree of magnification), seamless adjustment may be difficult when the spherical correction of the subject's eye exceeds the variable range of the variable-focus lens.

[0005] In view of the above-described conventional techniques, the present disclosure has as its technical object to provide a subjective optometry device and a subjective optometry program that can accurately measure the ocular refractive power of a subject's eye.

[0006] A subjective ophthalmological examination device according to a first aspect of the present disclosure is a subjective ophthalmological examination device for subjectively measuring the ocular refractive power of a subject's eye, and comprises: a corrective means arranged in front of the subject's eye and changing the optical properties of the visual target light beam emitted from a visual target presenting means; and a control means for controlling the corrective means, wherein the corrective means comprises a first corrective means for changing the spherical refractive power of the visual target light beam using a variable-focus element having a variable focal length; and a second corrective means for changing the spherical refractive power of the visual target light beam by switching and positioning optical elements, and the control means controls the first corrective means and the second corrective means to change the spherical refractive power of the visual target light beam.

[0007] A subjective optometry program according to a second aspect of the present disclosure is a subjective optometry program used in a subjective optometry device for subjectively measuring the ocular refractive power of the subject's eye, the subjective optometry program comprising a corrective means arranged in front of the eye to be examined and changing the optical characteristics of a visual target light beam emitted from a visual target presenting means, the corrective means including a first corrective means for changing the spherical refractive power of the visual target light beam using a variable-focus element with a variable focal length, and a second corrective means for changing the spherical refractive power of the visual target light beam by switching and positioning optical elements, the subjective optometry program being characterized in that, when executed by a processor of the subjective optometry device, the subjective optometry device is caused to execute a control step for controlling the corrective means, and the control step controls the first corrective means and the second corrective means to change the spherical refractive power of the visual target light beam.

[0008] FIG. 1 is an external view of the eye refractive power measurement unit supported at a standby position. FIG. 2 is an external view of the eye refractive power measurement unit supported at a measurement position. FIG. 3 is a schematic view showing the optical arrangement of the projection optical system during a distance test. FIG. 4 is a schematic view showing the optical arrangement of the projection optical system during a near test. FIG. 5 is a schematic view of the eye refractive power measurement unit. FIG. 6 is an internal configuration diagram of the lens unit. FIG. 7 is a horizontal cross-sectional view of the lens unit. FIG. 8 is an internal configuration diagram of a conventional lens unit. FIG. 9 is a horizontal cross-sectional view of the conventional lens unit. FIG. 10 is a diagram showing changes in the combined refractive power of a cylindrical lens and a cross cylinder lens included in a cylindrical lens disk. FIG. 11 is a schematic view of a control system of a subjective ophthalmology device. FIG. 12 is a diagram showing changes in the combined refractive power of a cylindrical lens and a cross cylinder lens included in a cylindrical lens disk.

[0009] <Overview> An overview of a subjective optometry device according to an embodiment of the present 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 symbols L and R indicate left and right eye use, respectively. Note that the items grouped in < > below can be used independently or in association with each other.

[0010] The subjective optometry device of this embodiment (e.g., the subjective optometry device 100) is a device for subjectively measuring the ocular refractive power of a subject's eye. For example, the ocular refractive power of the subject's eye may be measured to include at least one of spherical ocular refractive power, cylindrical ocular refractive power, and astigmatic axis angle. Of course, the subjective optometry device may also measure binocular vision function (e.g., at least one of prism amount, stereoscopic vision function, etc.), contrast sensitivity, etc. in addition to ocular refractive power.

[0011] The subjective optometry device of this embodiment is exemplified by a configuration including a target presenting means and a correction means, which will be described later, but is not limited thereto. The subjective optometry device may also be configured to include at least a correction means. For example, the subjective optometry device may include only a correction means, or may include a target presenting means and a correction means as a system.

[0012] The subjective optometry device of this embodiment may include a target presenting means that emits a target light beam toward the subject's eye.

[0013] For example, the optotype presenting means may be a display (e.g., the display 31). Also, for example, the optotype presenting means may be a light source and a DMD (Digital Micromirror Device). Also, for example, the optotype presenting means may be a light source and an optotype plate.

[0014] For example, the target light beam from the target presenting means may be guided directly toward the subject's eye. Alternatively, for example, the target light beam from the target presenting means may be guided toward the subject's eye via a light projection optical system (e.g., the light projection optical system 30). For example, the light projection optical system may have at least one optical element through which the target light beam emitted from the target presenting means passes. For example, the light projection optical system may have at least one optical element such as a lens, a mirror, or the like.

[0015] The subjective optometry device of this embodiment may include a correcting means, which is disposed in front of the subject's eye and changes the optical characteristics of the target light beam emitted from the target presenting means.

[0016] The correcting means may be configured to change at least one optical characteristic of the visual target light beam, such as spherical refractive power, cylindrical refractive power, and astigmatic axis angle. As an example, the correcting means may be an eye refraction measurement unit (e.g., eye refraction measurement unit 40) that switches and positions an optical element (e.g., optical element 51) in front of the subject's eye via an examination window (e.g., examination window 43). For example, the optical element may be at least one of a spherical lens, a cylindrical lens, a variable-focus lens, a cross cylinder lens, a rotary prism, a wavefront modulation element, etc. Of course, the optical element may be other than these. Furthermore, for example, the eye refraction measurement unit may have a lens disk (e.g., lens disk 50) on which multiple optical elements are arranged on the same circumference. In this case, the optical characteristics of the visual target light beam are changed by controlling a driving means (e.g., driving unit 52, driving unit 53, etc.) for controlling the lens disk.

[0017] <Changing the spherical refractive power of the visual target light beam> In this embodiment, the correcting means may include a first correcting means for changing the spherical refractive power of the visual target light beam using a variable optical element with a variable focal length, and a second correcting means for changing the spherical refractive power of the visual target light beam by switching and positioning the optical element.

[0018] The first correcting means is configured to change the spherical refractive power of the visual target light beam by changing the focal length of the variable-focus element when the variable-focus element is disposed in the optical path of the visual target light beam. For example, the first correcting means may be configured to switch between variable-focus elements and place them in front of the subject's eye. As an example, in this case, the variable-focus element may be provided on a lens disk of the eye refraction measurement unit. Also, for example, the first correcting means may be configured to fixedly place a variable-focus element in front of the subject's eye. As an example, in this case, the variable-focus element may be always placed in the examination window of the eye refraction measurement unit. For example, the variable-focus element may be one or more. For example, the variable-focus element may be a variable-focus lens. The variable-focus lens may be at least one of a liquid lens, a liquid crystal lens, an Alvarez lens, and the like.

[0019] The first correcting means may be capable of changing the spherical refractive power of the visual target light beam within a first refractive power range using a variable-focus element, i.e., may be capable of continuously changing the spherical refractive power of the visual target light beam using a variable-focus element.

[0020] The second correcting means is configured to change the spherical refractive power of the visual target light beam by switching an optical element disposed in the optical path of the visual target light beam. For example, the second correcting means may be disposed in front of the eye to be examined by switching the optical element. In this case, as an example, the optical element may be provided on a lens disk of the eye refractive power measurement unit. For example, the second optical element may be one or more. For example, the optical element may be a spherical lens. Note that, when a variable-focus element is used as the optical element of the second correcting means, the focal length of the variable-focus element may be set to a fixed distance.

[0021] The step by which the first correcting means can change the spherical refractive power of the visual target light beam may be configured to be smaller than the step by which the second correcting means can change the spherical refractive power of the visual target light beam. For example, the first correcting means may change the spherical refractive power of the visual target light beam in increments of 0.25D or less, and the second correcting means may change the spherical refractive power of the visual target light beam in increments greater than 0.25D. Of course, the value of the spherical refractive power step is merely an example and may be different. This allows the spherical refractive power of the visual target light beam to be continuously changed within the range of the first refractive power using the first correcting means. Furthermore, by using the first correcting means and the second correcting means in combination, the spherical refractive power of the visual target light beam can be expanded to a range of composite spherical refractive power wider than the first refractive power, allowing the spherical refractive power of the visual target light beam to be continuously changed within the range of composite refractive power.

[0022] The subjective ophthalmology device of this embodiment may also include a determination unit (e.g., a control unit 70). The determination unit determines whether to place an optical element of the second correcting unit in front of the subject's eye based on the modified spherical refractive power obtained by changing the spherical refractive power of the visual target light beam. In other words, the determination unit determines whether to place an optical element of the second correcting unit in front of the subject's eye based on the amount of spherical correction for correcting the subject's eye, which can be changed by changing the spherical refractive power of the visual target light beam. For example, the determination unit may determine whether to place an optical element based on whether the modified spherical refractive power of the visual target light beam exceeds a predetermined threshold. For example, the predetermined threshold may be a fixed value, or may be set by the examiner at an arbitrary value. This allows the variable-focus element of the first correcting unit and the optical element of the second correcting unit to be appropriately combined as needed.

[0023] The determination means may determine whether to place the optical element of the second correcting means in front of the eye to be examined based on the modified spherical refractive power of the visual target light beam and the range of the first refractive power of the first correcting means. In this case, a threshold value of the modified spherical refractive power of the visual target light beam may be set based on the range of the first refractive power of the first correcting means. For example, the predetermined threshold value may be a range from the maximum value to the minimum value of the first refractive power of the first correcting means. Furthermore, for example, the predetermined threshold value may be a range from a value around the maximum value to a value around the minimum value of the first refractive power of the first correcting means. For example, the predetermined threshold value may be a range from a value one step smaller than the maximum value to a value one step larger than the minimum value of the first refractive power. This makes it easy to understand cases where adjusting the spherical refractive power of the visual target light beam using the first correcting means alone is not sufficient, such as when the amount of spherical correction of the eye to be examined is a high-power number, and allows the variable-focus element of the first correcting means and the optical element of the second correcting means to be appropriately combined.

[0024] The subjective ophthalmology device of this embodiment may include a control unit (e.g., a control unit 70). The control unit controls the correcting unit. For example, the control unit controls the first correcting unit and the second correcting unit to change the spherical refractive power of the visual target light beam. For example, the spherical refractive power of the visual target light beam is changed to change the amount of spherical correction for correcting the eye to be examined. This allows the spherical refractive power of the visual target light beam to change seamlessly (without seams), thereby reducing the discomfort felt when the spherical refractive power of the visual target light beam is switched 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, when the spherical correction amount of the eye to be examined is switched from the first spherical correction amount to the second spherical correction amount), and the ocular refractive power of the eye to be examined can be measured accurately.

[0025] The control means may place the variable-focus element of the first correction means in the optical path of the visual target light beam and change the focal length of the variable-focus element to change the spherical refractive power of the visual target light beam and thereby change the amount of spherical correction of the test eye. For example, the control means may rotate the lens disk of the eye refraction measurement unit to place the variable-focus element on the lens disk in the test window (i.e., in the optical path of the visual target light beam). Also, for example, the control means may change the focal length of the variable-focus element in the test window of the eye refraction measurement unit.

[0026] The control means may change the spherical refractive power of the visual target light beam and change the amount of spherical correction of the eye to be examined by placing a predetermined optical element of the second correcting means in the optical path of the visual target light beam. For example, the control means may rotate a lens disk of the eye refraction measurement unit to place the optical element on the lens disk in the test window (i.e., in the optical path of the visual target light beam).

[0027] For example, when the spherical refractive power of the visual target light beam is changed using the variable-focus element of the first corrector, the variable-focus element of the first corrector may be positioned in the optical path of the visual target light beam, and the optical element of the second corrector may be removed from the optical path of the visual target light beam, and the variable-focus element may be changed to a predetermined focal length. Furthermore, when the spherical refractive power of the visual target light beam is changed using the optical element of the second corrector, the variable-focus element of the first corrector may be removed from the optical path of the visual target light beam, and the optical element of the second corrector may be positioned in the optical path of the visual target light beam. Alternatively, the variable-focus element may be changed to a focal length that results in 0D, and the optical element of the first corrector and the optical element of the second corrector may both be positioned in the optical path of the visual target light beam.

[0028] Of course, for example, when the spherical refractive power of the visual target light beam is changed by combining a variable-focus element of the first correcting means with an optical element of the second correcting means, the variable-focus element may be changed to a predetermined focal length while both the variable-focus element and the optical element are positioned in the optical path of the visual target light beam. By combining a variable-focus element with an optical element, the spherical refractive power of the visual target light beam can be significantly changed. Therefore, even when the spherical correction amount of the test eye is large, the ocular refractive power of the test eye can be accurately measured.

[0029] The control means may arrange at least the optical element of the second correcting means based on the modified spherical refractive power obtained by changing the spherical refractive power of the visual target light beam. That is, the control means may arrange only the optical element of the second correcting means based on the modified spherical refractive power of the visual target light beam, or may adjust the variable-focus element of the first correcting means and arrange the optical element of the second correcting means.

[0030] For example, the control means may control at least the second correcting means to switch and arrange the optical element when the modified spherical refractive power of the visual target light beam exceeds the range of the first refractive power of the first correcting means. In other words, at least the optical element may be arranged when the modified spherical refractive power of the visual target light beam exceeds the maximum value of the first refractive power of the first correcting means or the minimum value of the first refractive power. Furthermore, for example, the control means may arrange at least the optical element when the modified spherical refractive power of the visual target light beam is within the range of the first refractive power of the spherical refractive power of the first correcting means and exceeds a value around the maximum value of the first refractive power or a value around the minimum value of the first refractive power.

[0031] The control means may adjust the variable-focus element of the first corrective means using a table or an arithmetic expression that associates the modified spherical refractive power of the visual target light beam with the first refractive power of the first corrective means. The control means may also determine whether or not to provide the optical element of the second corrective means using a table or an arithmetic expression that associates the modified spherical refractive power of the visual target light beam with the second refractive power of the second corrective means. Of course, the control means may also adjust the variable-focus element of the first corrective means and determine whether or not to provide the optical element of the second corrective means using a table or an arithmetic expression that associates the modified spherical refractive power of the visual 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 obtained in advance through experiments or simulations and stored in the storage means.

[0032] The control means may control at least the second correcting means and switch the optical element based on the determination result of the determination means. For example, if the control means determines that the change in the spherical refractive power of the visual target light beam does not exceed a predetermined threshold, it may control the first correcting means and generate a predetermined spherical refractive power using a variable-focus element. Alternatively, if the control means determines that the change in the spherical refractive power of the visual target light beam exceeds a predetermined threshold, it may control at least the second correcting means and generate a predetermined spherical refractive power using at least an optical element. Furthermore, it may control both the first correcting means and the second correcting means according to the change in the spherical refractive power of the visual target light beam, and generate a predetermined spherical refractive power using a variable-focus element and an optical element. This allows for accurate measurement of the ocular refractive power of the subject's eye.

[0033] When adjusting the modified spherical power of the visual target light beam from a first modified spherical power to a second modified spherical power different from the first modified spherical power, the control unit may control only the first corrector and change the focal length of the variable-focus element according to the amount of change between the first modified spherical power and the second modified spherical power. For example, when the amount of change between the first modified spherical power before changing the spherical power of the visual target light beam and the second modified spherical power after changing the power is equal to or less than a predetermined threshold, the control unit may control only the first corrector. Alternatively, when the amount of change between the first modified spherical power and the second modified spherical power exceeds a predetermined threshold, the control unit may control both the first corrector and the second corrector, or only the second corrector. For example, the predetermined threshold may be a fixed value, or may be set by the examiner. This allows for easy adjustment of the spherical correction power required for correction of the subject's eye and smooth measurement of the subject's eye's refractive power.

[0034] <Changing the Cylindrical Refractive Power and Astigmatic Axis Angle of the Visual Target Light Beam> In this embodiment, the corrector may have a Stokes lens including a first cylindrical lens and a second cylindrical lens that can be independently rotated in front of the subject's eye. For example, the corrector may be capable of continuously changing the cylindrical refractive power of the visual target light beam by rotating the first cylindrical lens and the second cylindrical lens independently to change the relative angle of the astigmatic axes of the cylindrical lenses. Furthermore, for example, the corrector may be capable of continuously changing the astigmatic axis angle of the visual target light beam by rotating the first cylindrical lens and the second cylindrical lens integrally to change the composite axis angle of the cylindrical lenses. For example, the first cylindrical lens and the second cylindrical lens may be composed of two positive cylindrical lenses with the same focal length, or may be composed of a positive and a negative cylindrical lens with the same focal length.

[0035] The correcting means may have a corrective optical element for correcting a deviation in the spherical correction of the subject's eye, which deviation occurs when the first cylindrical lens and the second cylindrical lens are aligned with a composite axis angle. For example, the corrective optical element may be an element capable of changing the spherical refractive power of the visual target light beam. As an example, at least one of a variable-focus element with a variable focal length, an optical element with a fixed focal length, etc. may be used. Furthermore, for example, the corrective optical element may be one or more.

[0036] For example, the correcting means may switchably position a correcting optical element in front of the eye to be examined. As an example, in this case, the correcting optical element may be provided on a lens disk of the eye refraction measurement unit. Such a correcting optical element may be at least one of a variable focus element (e.g., a variable focus lens), an optical element (e.g., a spherical lens), etc. Also, for example, the correcting means may fixedly position a correcting optical element in front of the eye to be examined. As an example, in this case, the correcting optical element may be always positioned in the examination window of the eye refraction measurement unit. Such a correcting optical element may be a variable focus element (e.g., a variable focus lens).

[0037] The corrective means may have a corrective optical element for correcting the spherical correction of the subject's eye. For example, the corrective optical element may be an element capable of changing the spherical refractive power of the visual target light beam. As an example, at least one of a variable-focus element with a variable focal length, an optical element with a fixed focal length, etc. may be used. Also, for example, the corrective optical element may be one or more.

[0038] For example, the correcting means may switchably position a corrective optical element in front of the eye to be examined. As an example, in this case, the corrective optical element may be provided on a lens disk of the eye refraction measurement unit. Such a corrective optical element may be at least one of a variable focus element (e.g., a variable focus lens), an optical element (e.g., a spherical lens), etc. Also, for example, the correcting means may fixedly position a corrective optical element in front of the eye to be examined. As an example, in this case, the corrective optical element may be always positioned in the examination window of the eye refraction measurement unit. Such a corrective optical element may be a variable focus element (e.g., a variable focus lens).

[0039] In this embodiment, the correction optical element may be used both as a correction optical element for correcting the deviation in the amount of spherical correction that occurs when the first cylindrical lens and the second cylindrical lens of the Stokes lens are aligned to a composite axis angle, and as a correction optical element for adjusting the amount of spherical correction for correcting the subject's eye.

[0040] Furthermore, in this embodiment, the correction optical element for correcting the deviation of the spherical correction of the subject's eye may be combined with the variable-focus element with a variable focal length of the first correcting means, or the correction optical element for correcting the deviation of the spherical correction of the subject's eye may be combined with the optical element of the second correcting means. Similarly, in this embodiment, the correction optical element for adjusting the spherical correction of the subject's eye may be combined with the variable-focus element with a variable focal length of the first correcting means, or the correction optical element for adjusting the spherical correction of the subject's eye may be combined with the optical element of the second correcting means. This makes it possible to easily adjust the spherical correction of the subject's eye.

[0041] The subjective ophthalmological examination device of this embodiment may include an acquisition unit (e.g., a control unit 70). The acquisition unit acquires at least the cylindrical correction amount and the astigmatic axis correction amount for the subject's eye. For example, the acquisition unit may acquire the cylindrical correction amount and the astigmatic axis correction amount based on the refractive power (objective value) of the subject's eye measured objectively. Furthermore, for example, the acquisition unit may acquire the cylindrical correction amount and the astigmatic axis correction amount based on the refractive power (subjective value) of the subject's eye measured subjectively. As an example, the subjective value of the subject's eye may be the corrected refractive power closest to the plus side (full correction value) that provides the best visual acuity of the subject's eye, or the corrected refractive power (prescription value) that provides a predetermined visual acuity of the subject's eye. Of course, the acquisition unit may also acquire the spherical correction amount of the subject's eye along with the cylindrical refractive power and astigmatic axis angle of the subject's eye.

[0042] For example, the acquiring means may acquire the amount of cylindrical correction and the amount of astigmatic axis correction input by the examiner through operation of an operating means (e.g., the examiner controller 10). Furthermore, for example, the acquiring means may read an identifier for each subject and acquire the amount of cylindrical correction and the amount of astigmatic axis correction stored in the identifier. As an example, the identifier may be an ID, a character string, a one-dimensional code, a two-dimensional code, a color code, or the like. Furthermore, for example, the acquiring means may acquire the amount of cylindrical correction and the amount of astigmatic axis correction by receiving data measured using a device other than the subjective ophthalmology device of this embodiment.

[0043] The subjective optometry device of this embodiment may include an add power acquisition unit (e.g., the control unit 70). The add power acquisition unit acquires an add power corresponding to the correction amount of the subject's eye at a predetermined examination distance. For example, the add power may be a power based on at least one of the refractive power, accommodative power, age, etc. of the subject's eye.

[0044] For example, the add power acquisition means may acquire the add power input by the examiner operating the operation means. Also, for example, the add power acquisition means may read an identifier for each subject and acquire the add power stored in the identifier. Also, for example, the add power acquisition means may acquire the add power by receiving data measured using a device other than the subjective optometry device of this embodiment.

[0045] The subjective optometry device of this embodiment may include a control means. Note that the control means may be the same as the control means described above in "Changing the spherical refractive power of the visual target light beam." Of course, a different control means may also be provided separately.

[0046] The control unit may control the correction unit in an addition power test that measures the addition power corresponding to the correction amount at a predetermined test distance of the subject's eye. That is, the control unit may control the Stokes lens in the addition power test. For example, the control unit may change the composite axial angle between the first cylindrical lens and the second cylindrical lens to a predetermined axial angle based on the cylindrical correction amount and the astigmatic axial correction amount acquired by the acquisition unit. For example, such a composite axial angle may be an axial angle that takes into account the deviation of the astigmatic axial angle that occurs when an optical element and a cross cylinder lens are arranged to correct the subject's eye with the cylindrical correction amount and the astigmatic axial correction amount. The optical element here may be an optical element (e.g., a cylindrical lens) that can adjust at least one of the cylindrical correction amount and the astigmatic axial correction amount of the subject's eye by changing at least one of the cylindrical refractive power and the astigmatic axial angle of the target light beam. This allows the cylindrical refractive power and astigmatic axis angle of the visual target light beam to change seamlessly (without seams), thereby reducing the discomfort caused by the cylindrical refractive power of the visual target light beam switching from the first modified cylindrical refractive power to the second modified cylindrical refractive power different from the first modified cylindrical refractive power (in other words, the cylindrical correction of the test eye switching from the first modified cylindrical correction to the second modified cylindrical correction), allowing the ocular refractive power of the test eye to be measured with high accuracy.Similarly, this reduces the discomfort caused by the astigmatic axis angle of the visual target light beam switching from the first modified astigmatic axis angle to the second modified astigmatic axis angle different from the first modified astigmatic axis angle (in other words, the astigmatic axis correction of the test eye switching from the first modified astigmatic axis correction to the second modified astigmatic axis correction), allowing the ocular refractive power of the test eye to be measured with high accuracy.

[0047] The control means may correct a deviation in the spherical correction of the eye to be examined by placing a corrective optical element in front of the eye. In other words, a corrective optical element may be placed in the optical path of a visual target light beam and the spherical refractive power of the visual target light beam may be changed to correct a deviation in the spherical correction of the eye to be examined. For example, the control means may rotate a lens disk of the eye refraction measurement unit to place a variable-focus element on the lens disk in the examination window as a corrective optical element and change the focal length of the variable-focus element. Also, for example, the control means may rotate a lens disk of the eye refraction measurement unit to place an optical element on the lens disk in the examination window as a corrective optical element. This allows the spherical correction of the eye to be appropriately corrected by the corrective optical element.

[0048] The control means may use a variable-focus element with a variable focal length as the correction optical element, and change the spherical refractive power of the variable-focus element to correct deviations in the amount of spherical correction of the subject's eye. For example, because deviations in the amount of spherical correction caused by adjustment of a Stokes lens are small, the accuracy of correction can be improved by finely adjusting the deviations using the variable-focus element.

[0049] The control means may set the composite axial angle using a table or an arithmetic expression that associates the amount of cylindrical correction and the amount of astigmatic axis correction of the subject's eye with the composite axial angle between the first cylindrical lens and the second cylindrical lens. The control means may also position the corrective optical element using a table or an arithmetic expression that associates the amount of cylindrical correction and the amount of astigmatic axis correction of the subject's eye with the deviation of the astigmatic axial angle correction that accompanies the setting of the composite axial angle between the first cylindrical lens and the second cylindrical lens. Of course, the control means may also set the composite axial angle and position the corrective optical element using a table or an arithmetic expression that associates the amount of cylindrical correction and the amount of astigmatic axis correction of the subject's eye with the composite axial angle between the first cylindrical lens and the second cylindrical lens and the deviation of the astigmatic axial correction that accompanies the setting of the composite axial angle. For example, such a table may be obtained in advance by experiment or simulation and stored in the storage means.

[0050] The control means may switch between a first state in which the first cylindrical lens and the second cylindrical lens are aligned with a composite axis angle and a second state in which a corrective optical element based on the addition 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 a corrective optical element in the optical path of the visual target light beam and changing the spherical refractive power of the visual target light beam. For example, the control means may rotate a lens disk of the eye refraction measurement unit to arrange a variable-focus element on the lens disk in the examination window as the corrective optical element and change the focal length of the variable-focus element. Also, for example, the control means may rotate the lens disk of the eye refraction measurement unit to arrange an optical element on the lens disk in the examination window as the corrective optical element. This allows the spherical correction of the subject's eye to be appropriately corrected by the corrective optical element. With the deviation amount of the spherical correction of the eye being corrected, the state in which the additional power is not given to the eye can be switched to the state in which the additional power is given, and therefore the optimal additional power for the eye can be measured with high accuracy.

[0051] The present disclosure is not limited to the devices described in the present embodiment. For example, terminal control software (programs) that perform the functions of the above embodiments may be supplied to a device or system via a network or various storage media, and a control device (e.g., a CPU) of the device or system may read and execute the program.

[0052] <Example> An example of a subjective optometry device in this embodiment will be described. Figures 1A and 1B are external views of a subjective optometry device 100. Figure 1A shows a state in which an eye refractive power measurement unit 40 is supported in a standby position. Figure 1B shows a state in which the eye refractive power measurement unit 40 is supported in a 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 eye refractive power measurement unit 40, etc.

[0053] The housing 1 has a light projection optical system 30 therein. The presentation window 2 transmits a visual target light beam emitted by the light projection optical system 30. The visual target light beam is projected onto the subject's eye E through the presentation window 2. When an eye refractive power measuring unit 40 is disposed between the subject's eye E and the presentation window 2 (see FIG. 1B ), the visual target light beam is projected onto the subject's eye E through the presentation window 2 and a test window 43 (described later). This presents a test visual target to the subject's eye E.

[0054] The holding unit 4 holds the eye refractive power measurement unit 40. For example, the holding unit 4 moves an arm by driving a drive unit (motor or the like) not shown, thereby moving the eye refractive power measurement unit 40 connected to the arm. This allows the eye refractive power measurement unit 40 to be switched between a standby position and a measurement position.

[0055] The examiner's controller 10 is used by the examiner to operate the subjective ophthalmological examination device 100. The examiner's controller 10 includes a switch unit 11, a monitor 12, etc. The switch unit 11 inputs signals for performing various settings (e.g., selection of an optotype to be presented to the examinee, etc.). The monitor 12 displays various information (e.g., measurement results of the examinee's eye E, etc.). The monitor 12 may also function as a touch panel that doubles as the switch unit 11. Signals from the examiner's controller 10 are output to the control unit 60 via wired or wireless communication.

[0056] 2A and 2B are schematic diagrams of the light-projecting optical system 30. Fig. 2A shows the optical arrangement during a distance test. Fig. 2B shows the optical arrangement during a near test. The light-projecting optical system 30 projects a visual target light beam toward the subject's eye E. For example, the light-projecting optical system 30 includes a display 31, a plane mirror 32, a concave mirror 33, a near / far switcher 34, and the like.

[0057] The display 31 displays a visual target (e.g., a fixation target, a test visual target, etc.). A visual target light beam emitted from the display 31 forms an image on the fundus of the subject's eye E, thereby presenting the visual target to the subject's eye E. For example, the display 31 may be an LCD (Liquid Crystal Display), an organic EL (Electro Luminescence), a plasma display, etc.

[0058] The plane mirror 32 reflects the visual target light beam from the display 31 and guides it to the concave mirror 33. The plane mirror 32 also reflects the visual target light beam from the display 31 and guides it to the subject's eye E. For example, the plane mirror 32 is positioned so that the distance (presentation distance) from the subject's eye E to the display 31 during a near vision test of the subject's eye E is optically 40 cm. Note that instead of the plane mirror 32, it is also possible to use a reflecting member such as a prism, a beam splitter, or a half mirror.

[0059] The concave mirror 33 reflects the visual target light beam from the display 31 and guides it to the plane mirror 32. For example, the concave mirror 33 is positioned so that the distance (presentation distance) from the subject's eye E to the display 31 during a distance test of the subject's eye E is optically 5 m. Note that instead of the concave mirror 33, it is also possible to use a reflective member such as an aspherical mirror or a free-form mirror. It is also possible to use a lens or the like instead of the concave mirror 33.

[0060] The distance switching unit 34 switches the position of the display 31 between a distance test and a near test of the subject's eye E. For example, the distance switching unit 34 moves the holder by driving a drive unit (motor or the like) not shown, thereby moving the display 31 held by the holder. This allows the display 31 to be switched between a distance position and a near position.

[0061] For example, during a distance vision test of the subject's eye E, the display screen of the display 31 is directed toward the rear of the housing 1 (see FIG. 2A ). The visual target light beam from the display 31 passes through the optical axis L1 and is incident on the plane mirror 32, where it is reflected in the direction of the optical axis L2. The visual target light beam also passes through the optical axis L2 and is incident on the concave mirror 33, where it is reflected in the direction of the optical axis L3. The visual target light beam also passes through the optical axis L3 and is reflected in the direction of the optical axis L4 by the plane mirror 32. As a result, the visual target light beam that has passed through each optical member inside the housing 1 and is emitted to the outside of the housing 1 is projected onto the subject's eye E.

[0062] For example, during a near vision test of the subject's eye E, the display screen of the display 31 is directed toward the top surface of the housing 1 (see FIG. 2B). The visual target light beam from the display 31 passes through the optical axis L3 and enters the plane mirror 32, and is reflected by the plane mirror 32 in the direction of the optical axis L4. As a result, the visual target light beam that has passed through each optical member inside the housing 1 and is emitted to the outside of the housing 1 is projected onto the subject's eye E.

[0063] <Eye Refractive Power Measurement Unit (Corrective Optical System)> Fig. 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 subject's eye E. The eye refractive power measurement unit 40 is also used as a corrective optical system. The corrective optical system is disposed in the optical path of the light projection optical system 30, and changes the optical characteristics of the visual 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, and the like.

[0064] The forehead rest 41, against which the subject's forehead rests, fixes the subject's eye E at a predetermined examination position and maintains a constant distance from the subject's 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 examination windows 43 (left examination window 43L and right examination window 43R).

[0065] 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 a driving unit 45 (left driving unit 45L and right driving 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 a driving unit 46. For a detailed configuration of the moving unit 44, see, for example, Japanese Patent Application Laid-Open No. 2004-329345.

[0066] 4A and 4B are schematic diagrams of the lens unit 42. Fig. 4A is a diagram showing the internal configuration of the lens unit 42. Fig. 4B is a horizontal cross-sectional view of the lens unit 42. Note that Figs. 4A and 4B only show the left lens unit 42L, and do not show the right lens unit 42R. For example, the lens unit 42 includes a variable-focus lens 61, a Stokes lens 62, and a lens disk 50.

[0067] The variable-focus lens 61 is fixedly disposed within the lens unit 42. The variable-focus lens 61 adjusts its spherical refractive power in accordance with the magnitude of the applied voltage and changes its focal position, thereby generating a spherical refractive power that changes continuously within a predetermined range. For example, in this embodiment, the variable-focus lens 61 can generate a spherical refractive power ranging from −5.00 D to +5.00 D.

[0068] The Stokes lens 62 is rotatably disposed within the lens unit 42. The Stokes lens 62 is composed 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 the same focal length. Note that the cylindrical lenses 62a and 62b may also be two positive cylindrical lenses with the same focal length.

[0069] The cylindrical lenses 62a and 62b are independently rotated around the optical axis L4 by driving the rotation mechanisms 63a and 63b, respectively. By changing the rotation angle of at least one of the cylindrical lenses 62a and 62b and providing a difference in the axial angles of the respective cylindrical lenses, it is possible to generate a cylindrical refractive power that varies continuously within a predetermined range. For example, in this embodiment, a cylindrical refractive power of -10.00D to +10.00D can be generated. Furthermore, by changing the rotation angles of the cylindrical lenses 62a and 62b together while maintaining the difference in axial angles between them (i.e., by changing the composite axial angle of the cylindrical lenses 62a and 62b), it is possible to adjust the astigmatic axial angle that varies continuously within a predetermined range. For example, in this embodiment, the astigmatic axial angle can be adjusted from 1 degree to 180 degrees.

[0070] 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 around the disk center by driving a drive unit 52. Furthermore, each optical element 51 is rotated around an optical axis L4 by driving a drive unit 53. As a result, the desired optical element 51 is switched and positioned in the inspection window 43 at the desired angle.

[0071] The lens disk 50 may consist of one lens disk or multiple lens disks. For example, in this embodiment, a first auxiliary lens disk 50a and a second auxiliary lens disk 50b are provided. The first auxiliary lens disk 50a is provided with optical elements 51 such as a polarizing filter, a red filter / green filter, a dispersion prism, and a Maddox lens. The second auxiliary lens disk 50b is provided with optical elements 51 such as a clear lens, a rotary prism, an autocross cylinder lens, a first spherical lens 51a, and a second spherical lens 51b. For example, the clear lens is provided with a mark for aligning the interpupillary distance of the subject's eye E. For example, the first spherical lens 51a is a lens having a spherical power equivalent to -10.00D when converted to a spectacle-wearing position. For example, the second spherical lens 51b is a lens having a spherical power equivalent to +10.00D when converted to a spectacle-wearing position. For example, the spherical refractive power of the first spherical lens 51 a and the second spherical lens 51 b is greater than a predetermined range of the spherical refractive power of the variable-focus lens 61 .

[0072] The spectacle wearing position in this embodiment refers to the position where the spectacle lenses are assumed to be placed in front of the subject's eye E when the subject wears the eyeglasses, and is the position of the optical element (i.e., the variable-focus lens 61) that is closest to the subject's eye E. More specifically, it is position G of the rear surface of the variable-focus lens 61. The distance from the corneal apex position of the subject's eye E to the position of the variable-focus lens 61 (position G of the rear surface of the variable-focus lens 61) can also be considered as the corneal vertex distance VD.

[0073] <Adjustable 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 using only the variable-focus lens 61 can be expanded. For example, by setting the variable-focus lens 61 to any value between 0D and −5.00D and combining it with the first spherical lens 51a (−10.00D), it is possible to generate a spherical refractive power between −10.00D and −15.00D. For example, by setting the variable-focus lens 61 to any value between 0D and +5.00D and combining it with the second spherical lens 51b (+10.00D), it is possible to generate a spherical refractive power between +10.00D and +15.00D.

[0074] That is, in this embodiment, a spherical refractive power of -5.00D to +5.00D can be seamlessly generated using only the variable-focus lens. Also, by arranging the first spherical lens 51a or the second spherical lens 51b in the test 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.

[0075] For example, the amount of spherical correction of the subject's eye E, the spherical refractive power of the variable-focus lens 61, and the spherical refractive power of the first spherical lens 51 a and the second spherical lens 51 b may be associated in advance. For example, the association may be established in advance so that when the amount of spherical correction of the subject's eye E exceeds the spherical refractive power adjustable by the variable-focus lens 61, the first spherical lens 51 a and the second spherical lens 51 b generate spherical refractive power (in other words, the first spherical lens 51 a or the second spherical lens 51 b is disposed). As an example, a lookup table or the like may be prepared in advance and stored in the memory 75 for referencing the value of the spherical refractive power of the variable-focus lens 61 and the value of the spherical refractive power of the first spherical lens 51 a and the second spherical lens 51 b based on the amount of spherical correction of the subject's eye E.

[0076] <Reproduction of the cross cylinder lens arrangement> Here, a lens unit provided in a conventional eye refractive power measurement unit will be briefly described. Figures 5A and 5B are schematic diagrams of a conventional lens unit 200. Figure 5A is a diagram showing the internal configuration of the conventional lens unit 200. Figure 5B is a horizontal cross-sectional view of the conventional lens unit 200. Note that Figures 5A and 5B only show the left lens unit, and do not show the right lens unit.

[0077] The lens unit 200 includes a plurality of lens disks 210. For example, in a direction away from the subject's eye E, a strong spherical lens disk 210a, a weak spherical lens disk 210b, a strong cylindrical lens disk 210c, a weak cylindrical lens disk 210d, a first auxiliary lens disk 210e, and a second auxiliary lens disk 210f are provided. The strong spherical lens disk 210a includes spherical lenses ranging from -18.00D to +15.00D at 3.00D intervals. The weak spherical lens disk 210b includes spherical lenses ranging from -1.00D to +1.75D at 0.25D intervals. The strong cylindrical lens disk 210c includes cylindrical lenses ranging from -1.50D to -7.50D at 1.50D intervals, converted into the eyeglass wearing position. The weak cylindrical lens disk 210d is provided with cylindrical lenses of -0.25D to -1.25D at 0.25D intervals, converted to the eyeglass wearing position. The first auxiliary lens disk 210e is provided with a polarizing filter, red filter / green filter, dispersion prism, Maddox lens, etc. The second auxiliary lens disk 210f is provided with a clear lens, rotary prism, autocross cylinder lens, cross cylinder lens, etc. For details of the lens unit 200, please refer to, for example, Japanese Patent Application Laid-Open No. 2007-125125.

[0078] The conventional lens unit 200 includes a strong cylindrical lens disk 210c, a weak cylindrical lens disk 210d, and a cross cylinder lens. For example, a cross cylinder lens is a lens formed by combining cylindrical lenses with the same cylindrical refractive power but opposite signs, with their astigmatic axis angles perpendicular to each other. As an example, it is a lens formed by combining cylindrical lenses with -0.25D and +0.25D, with their astigmatic axis angles perpendicular to each other. On the other hand, the lens unit 42 of this embodiment includes the Stokes lens 62 (cylindrical lenses 62a and 62b) instead of the strong cylindrical lens disk 210c and the weak cylindrical lens disk 210d, and does not include a cross cylinder lens.

[0079] 6 is a diagram showing the change in the combined refractive power of the cylindrical lens and cross cylinder lens of the cylindrical lens disk in the conventional lens unit 200. For example, a cylindrical lens 250 of a weak cylindrical lens disk 210d is switched and placed in front of the eye E to be examined. As an example, the cylindrical lens 250 has a cylindrical refractive power of -1.00D and is rotated so that its astigmatic axis angle is 135 degrees. In this case, the refractive power of the cylindrical lens 250 changes according to 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.

[0080] Furthermore, for example, the cross cylinder lens 260 of the first auxiliary lens disk 210e is switched and positioned in front of the subject's eye E. As an example, the cross cylinder lens 260 is rotated so that +0.25D becomes 90 degrees. At this time, the refractive power of the cross cylinder lens 260 changes according to 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.

[0081] For example, when both the cylindrical lens 250 and the cross cylinder lens 260 are alternately positioned in front of the eye E, a composite refractive power is generated by combining the refractive powers of the respective lenses. At this time, the composite refractive power varies according to 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. Note that, for example, the sine curve α of the refractive power of the cylindrical lens 250 has its apex located at 135 degrees, whereas the sine curve γ of the composite refractive power of the cylindrical lens 250 and the cross cylinder lens 260 has its apex shifted to 122 degrees.

[0082] In this embodiment, by setting the composite axial angle of the cylindrical lenses 62a and 62b in the Stokes lens 62 in consideration of the amount of deviation in the astigmatic axis angle that occurs when assuming the arrangement of the cylindrical lens 250 and the cross cylinder lens 260, it is possible to create the state in which the cylindrical lens 250 and the cross cylinder lens 260 are arranged using only the Stokes lens 62. For example, the arrangement of the cylindrical lens 250 and the cross cylinder lens 260 described above can be reproduced by adjusting the difference in axial angle between the cylindrical lenses 62a and 62b to a difference that generates a cylindrical refractive power of −1.00 D, and by arranging the composite axial angle of the cylindrical lenses 62a and 62b to be 122 degrees instead of 135 degrees.

[0083] For example, the cylindrical correction amount and astigmatic axis angle of the subject's eye E may be associated in advance with the composite axis angle of the cylindrical lenses 62 a and 62 b. As an example, a lookup table for referencing the values ​​of the astigmatic axis angles of the cylindrical lenses 62 a and 62 b based on the cylindrical correction amount and astigmatic axis correction amount of the subject's eye E may be prepared in advance and stored in the memory 75.

[0084] In the conventional lens unit 200, when the spherical lens, cylindrical lens 250, and cross cylinder lens 260 are positioned in front of the subject's eye E, the spherical equivalent value of the subject's eye E is taken into consideration. For example, when the cylindrical lens 250 is switched to change the cylindrical power by 0.25D (one step), a spherical power of 0.125D is generated. For example, if the spherical lenses are arranged at 0.25D intervals, when the cylindrical power is changed by 0.50D (two steps), the spherical power can be changed by switching the spherical lens, resulting in a correction that takes into account the spherical equivalent value. In this embodiment, the variable-focus lens 61 is used to easily perform correction that takes into account changes in spherical power due to changes in cylindrical power. Furthermore, when the cylindrical power is changed finely using the Stokes lens 62, the spherical power changes in various ways, but correction can also be easily performed in such cases.

[0085] <Controller> Fig. 7 is a schematic diagram of the control system of the subjective optometry device 100. For example, the controller 70 includes a CPU (processor), RAM, ROM, etc. The CPU controls the driving 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. The controller 70 may be configured with multiple controllers (i.e., multiple processors).

[0086] The control unit 70 is connected to the display 31, the examiner's controller 10, a non-volatile memory 75 (hereinafter referred to as memory 75), etc. The control unit 70 is also connected to a drive unit for the holding unit 4, a drive unit for the near / far switching unit 34, a drive unit for the eye refractive power measurement unit 40 (drive units 45, 46, 52, 53), etc.

[0087] The memory 75 is a non-transitory storage medium that can retain its contents even when the power supply is cut off. For example, the memory 75 may be a hard disk drive, a flash ROM, a USB memory, or the like.

[0088] <Control Operation> The control operation of the subjective optometry device 100 will be described.

[0089] 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 subject's eye E is a predetermined distance (e.g., 12 mm). The examiner also operates the examiner controller 10 to input the interpupillary distance of the subject's eye. The control unit 70 adjusts the spacing of the lens units 42 to align the examination window 43 with the interpupillary distance.

[0090] <Setting the Initial Correction Amount> The examiner operates the examiner controller 10 to input the objective ocular refractive power (objective value) previously obtained by objective measurement of the subject's eye E as the initial correction amount of the subject's eye E. That is, the initial spherical correction amount, initial cylindrical correction amount, and initial astigmatic axis correction amount are input. Based on the above-mentioned lookup table, the control unit 70 applies a voltage to the variable-focus lens 61 and rotates the Stokes lens 62 and the lens disk 50. Note that the variable-focus lens 61, Stokes lens 62, and lens disk 50 may be controlled sequentially or substantially simultaneously.

[0091] In this embodiment, an example is given in which the objective refractive power (objective value) of the subject's eye E is a spherical refractive power of −6.50 D, a cylindrical refractive power of −1.00 D, and an astigmatic axial angle of 135 degrees. In this case, the initial correction amounts for the subject's eye E may be input as a spherical correction amount of −6.50 D, a cylindrical correction amount of −1.00 D, and an astigmatic axial correction amount of 135 degrees. For example, the control unit 70 adjusts the spherical refractive power of the variable-focus lens 61 to +3.50 D. Furthermore, for example, the control unit 70 changes the difference in axial angle between the cylindrical lenses 62 a and 62 b to adjust the cylindrical refractive power to −1.00 D. Furthermore, for example, the control unit 70 adjusts the composite axial angle between the cylindrical lenses 62 a and 62 b to 135 degrees. Furthermore, for example, the control unit 70 places the opening of the first auxiliary lens disk 50 a and the first spherical lens 51 a (spherical refractive power −10.00 D) of the second auxiliary lens disk 50 b in the inspection window 43 .

[0092] This results in correction so that the visual target light beam from the display 31 is focused on the retina of the subject's eye E. In other words, the subject's eye E is corrected with a spherical correction of −6.50, which is a combination of the variable-focus lens 61 and the first spherical lens 51a. The subject's eye E is also corrected with a cylindrical correction of −1.0D and an astigmatic axis correction of 135 degrees by the Stokes lens 62.

[0093] <Distance Visual Acuity Test> After correcting the eye E to be examined with the initial correction amount, the examiner operates the examiner controller 10 to start a distance visual acuity test of the eye E to be examined at a predetermined distance (here, the distance test distance). The control unit 70 switches the display 31 to a distance position. The control unit 70 also causes a Landolt ring target having a predetermined visual acuity value to be displayed on the display 31 as the initial visual target. As an example, a Landolt ring target having a visual acuity value of 0.8 is displayed as the initial visual target.

[0094] The examiner operates the examiner controller 10 to switch between Landolt ring targets and ask the examinee the direction of the gap in the ring of the Landolt ring target. For example, if the examinee's answer is correct, the visual acuity value of the Landolt ring target is switched to a visual acuity value one level higher. That is, the visual acuity value of the Landolt ring target is increased by one increment, 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 examinee's answer is incorrect, the visual acuity value of the Landolt ring target is switched to a visual acuity value one level lower. That is, the visual acuity value of the Landolt ring target is decreased by one increment, 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 procedures to determine the highest visual acuity value of the Landolt ring target that the examinee's eye E can read.

[0095] Next, the examiner operates the examiner controller 10 to change the amount of correction for the subject's eye E while asking the subject which direction the gap in the ring of the Landolt ring is. For example, if the subject's answer is correct, the amount of spherical correction is changed to a correction amount that is one level weaker. That is, the amount of spherical correction is decreased by one step and changed to a value smaller than the current value. As an example, by changing the spherical refractive power of the variable-focus lens 61 from +3.50 D to +3.25 D, the amount of spherical correction for correcting the subject's eye E is changed from -6.50 D to -6.25 D. For example, if the subject's answer is incorrect, the amount of spherical correction is changed to a correction amount that is one level stronger. That is, the amount of spherical correction is increased by one step and changed to a value larger than the current value. As an example, by changing the spherical refractive power of the variable-focus lens 61 from +3.50D to +3.75D, the amount of spherical correction is switched from -6.50D to -6.75D.

[0096] The control unit 70 positions the first spherical lens 51a or the second spherical lens 51b as necessary according to the amount of spherical correction to be applied to the subject's eye E. Of course, the amount of cylindrical correction and the amount of astigmatism axis correction may be switched along with the amount of spherical correction according to the subject's response. In this embodiment, the variable-focus lens 61 allows the amount of spherical correction to be changed in increments of less than -0.25D. Similarly, the cylindrical lenses 62a and 62b of the Stokes lens 62 allow the amount of cylindrical correction to be changed in increments of less than -0.25D. The examiner repeats these procedures to determine the most positive corrective refractive power value (i.e., the full correction value) that provides the best visual acuity for the subject's eye E.

[0097] <Addition Test> After completing the distance vision test of the subject's eye E, the examiner operates the examiner controller 10 to start the addition test with the subject's eye E corrected to a fully corrected value at a predetermined distance (distance test distance). For example, the examiner determines the need for addition and sets the initial addition power based on at least one of the subject's age, the accommodation power of the subject's eye E, the refractive power of the subject's eye E, etc. Of course, the control unit 70 may automatically determine and set the need for addition and the initial addition power.

[0098] In this embodiment, the full correction value (subjective value) of the subject's eye E is determined to be -6.00 D of spherical correction, -1.25 D of cylindrical correction, and 135 degrees of astigmatism axis correction, and the initial add power is set to +1.00 D. In an add power test using a conventional lens unit 200, the subject's eye E is corrected to the full correction value, and a cross cylinder lens is positioned so that -0.50 D corresponds to 0 degrees and +0.50 D corresponds to 90 degrees, and the initial add power is increased or decreased. In this embodiment, the state in which the subject's eye E is corrected to the full correction value and the cross cylinder lens is positioned is reproduced using the Stokes lens 62, and then the initial add power is increased or decreased.

[0099] First, the control unit 70 corrects the eye E to a perfect correction value and creates a first state assuming that a cross cylinder lens is placed. The control unit 70 assumes that a lens with a cylindrical refractive power of −1.25D is placed at 135 degrees as the cylindrical lens 250 of the conventional lens unit 200, and that the cross cylinder lens 270 is placed so that +0.50D forms an angle of 90 degrees, and rotates the cylindrical lenses 62a and 62b of the Stokes lens 62 to correct the cylindrical correction amount of the eye E to −1.25D and the astigmatic axis angle to 135 degrees.

[0100] 8 is a diagram showing the change in the composite refractive power of the cylindrical lens 250 and the cross cylinder lens 270. The refractive power of the cylindrical lens 250 changes according to a sine curve α that passes through −1.25D at 45 degrees, and the refractive power of the cross cylinder lens 270 changes according to a sine curve β that passes through +0.50D at 90 degrees. The sine curve γ of the composite refractive power of the cylindrical lens 250 and the cross cylinder lens 270 has its apex at 116 degrees. Therefore, the control unit 70 adjusts the difference in axial angle between the cylindrical lenses 62a and 62b of the Stokes lens 62 to a difference that generates a cylindrical refractive power of −1.25D, and positions the composite axial angle of the cylindrical lenses 62a and 62b at 116 degrees instead of 135 degrees. As a result, the eye E is corrected by reproducing a state in which a cylindrical correction (CYL) of −1.25 D, an astigmatism axis correction (AXIS) of 135 degrees, and a cross cylinder lens 270 (+0.50 D in the 90-degree direction) are combined.

[0101] At this time, a spherical refractive power ΔS is generated due to the deviation between the astigmatic axis correction of the eye E and the composite axial angle of the cylindrical lenses 62a and 62b. The spherical refractive power ΔS is a quantity that appears as the difference between the refractive power of the cylindrical lens 250 and the composite refractive power of the cylindrical lens 250 and the cross cylinder lens 260 (in FIG. 8, this is the difference between the vertical axes at the apexes of the sine curves α and γ). Note that the spherical refractive power ΔS changes depending on the deviation between the astigmatic axis correction and the composite axial angle, but this is a small amount, smaller than one step (0.25D). For example, in this embodiment, the spherical refractive power ΔS is −0.15D.

[0102] The control unit 70 changes the spherical refractive power of the variable-focus lens 61 to +4.00 D and switches and positions the first spherical lens 51a (-10.00 D), thereby correcting the eye E with a spherical correction of -6.00 D. However, because the Stokes lens 62 generates a spherical refractive power ΔS, the spherical refractive power of the variable-focus lens 61 is actually set to +3.85 D, and the eye E is corrected with a spherical correction of -6.15 D. For example, by using the variable-focus lens 61 in this manner, it is possible to finely adjust the numerical values ​​taking into account the spherical refractive power ΔS.

[0103] The examiner operates the examiner's controller 10 to display a cross grid optotype on the display 31. The examiner also operates the examiner's controller 10 and presses a switch (not shown) to switch between a first state, which assumes that the subject's eye E has been fully corrected and a cross cylinder lens has been placed, and a second state, which assumes that an initial add power of +1.00 D has been added to the first state. The control unit 70 changes the spherical refractive power of the variable-focus lens 61 in response to an operation signal from the switch (not shown). In this example, the spherical refractive power of the variable-focus lens 61 is changed to +3.85 D or +4.85 D. This switches the amount of spherical correction for the subject's eye E between −6.00 D (actually −6.15 D) without any initial add power and −5.00 D (actually −5.15 D) with an initial add power.

[0104] The examiner asks the subject how the cross grid target looks and changes the add power depending on the subject's answer. The control unit 70 changes the spherical refractive power of the variable-focus lens 61 according to the spherical refractive power to be added to the subject's eye E, and positions the first spherical lens 51 a or the second spherical lens 51 b as necessary. The examiner repeats this procedure until the stage at which the vertical and horizontal lines of the cross grid target look even is determined to be the appropriate add power for the subject's eye E.

[0105] <Near Vision Test> After completing the addition power test for the subject's eye E, the examiner operates the examiner's controller 10 to start a near vision test for the subject's eye E at a predetermined distance (here, the near vision test distance). The control unit 70 switches the display 31 to the near vision position. In the conventional lens unit 200, the cross cylinder lens 270 is removed when transitioning from the addition power test to the near vision test. Therefore, in this embodiment, the variable-focus lens 61 and the Stokes lens 62 (cylindrical lenses 62a and 62b) are adjusted to reproduce the state in which the cross cylinder lens 270 is removed. The best visual acuity value is also determined in the near vision test, but this procedure is basically the same as in the distance vision test and will not be described here.

[0106] As described above, for example, the subjective ophthalmology device of this embodiment controls a first correcting means for changing the spherical refractive power of the visual target light beam using a variable-focus element (here, the variable-focus lens 61) with a variable focal length, and a second correcting means for changing the spherical refractive power of the visual target light beam by switching between optical elements (here, the first spherical lens 51a and the second spherical lens 51b), thereby changing the spherical refractive power of the visual target light beam. For example, the variable-focus element can continuously change the spherical refractive power, which allows for fine adjustment of the amount of spherical correction of the test eye to appropriately correct the test eye. However, on the other hand, it is technically difficult to generate a spherical refractive power of a high power using a variable-focus element, and changing the spherical refractive power using only the variable-focus element may not be sufficient for cases where the amount of spherical correction of the test eye is large. In this embodiment, by combining the variable-focus lens with the first spherical lens or the second spherical lens as needed, it is possible to generate a spherical refractive power of a high power. Therefore, even when the amount of spherical correction of the eye to be examined is large, the eye to be examined can be appropriately corrected and the ocular refractive power of the eye to be examined can be measured with high accuracy.

[0107] For example, in the past, when a spherical lens was switched in front of the subject's eye, the subject would feel uncomfortable due to the sudden change from one spherical refractive power to another (in other words, a seam in the spherical refractive power) or would feel annoyed due to the noise generated when the spherical lens was switched. In this embodiment, by adjusting the desired spherical refractive power using a variable-focus component, the spherical refractive power changes seamlessly (without seams), allowing the measurement to proceed without any discomfort. Furthermore, since no noise is generated when the spherical lens is switched, annoyance can be reduced.

[0108] Furthermore, for example, in the subjective ophthalmology device of this embodiment, the first correcting means can change the spherical refractive power of the visual target light beam within a first refractive power range, and when the changed spherical refractive power of the visual target light beam exceeds the first refractive power range of the spherical refractive power of the first correcting means, at least the optical element is switched and positioned. For example, when a variable-focus element is positioned in front of the subject's eye, the spherical refractive power can be continuously changed within the first refractive power range, allowing for smooth subjective examination of the subject's eye. Furthermore, for example, when a variable-focus element and an optical element are positioned in front of the subject's eye, the spherical refractive power (composite spherical refractive power) can be expanded by the optical element, and the composite spherical refractive power can be continuously changed by the variable-focus element, allowing for smooth subjective examination of the subject's eye.

[0109] Furthermore, for example, in the subjective ophthalmology device of this embodiment, the number of steps by which the first correcting means can change the spherical refractive power of the visual target light beam is smaller than the number of steps by which the second correcting means can change the spherical refractive power of the visual target light beam. This allows the spherical refractive power of the visual target light beam to be changed more precisely using a variable-focus element. Furthermore, even when a variable-focus element and an optical element are combined, the spherical refractive power of the visual target light beam can be changed more precisely within the range of their combined spherical refractive power.

[0110] Furthermore, for example, in an addition power test for measuring the addition power corresponding to the correction amount at a predetermined test distance of the subject's eye, the subjective ophthalmological examination device of this embodiment controls independently rotatable Stokes lenses in front of the subject's eye, and changes the composite axial angle of the first cylindrical lens and the second cylindrical lens to a predetermined axial angle based on the cylindrical correction amount and the astigmatic axial correction amount of the subject's eye, where the composite axial angle is an axial angle that takes into account the deviation of the astigmatic axial correction amount that occurs when an optical element and a cross cylinder lens are arranged to correct the subject's eye with the cylindrical correction amount and the astigmatic axial correction amount. For example, when a Stokes lens is arranged in front of the subject's eye, the cylindrical refractive power can be continuously changed by rotating the two cylindrical lenses individually to adjust the difference in axial angle, and the astigmatic axial angle can be continuously changed by rotating the two cylindrical lenses together to adjust the composite axial angle. In this embodiment, the deviation in the astigmatic axis correction amount caused by the Stokes lens is taken into consideration, so that the cylindrical correction amount and astigmatic axis correction amount of the test eye can be appropriately corrected, and the ocular refractive power of the test eye can be measured with high accuracy.

[0111] For example, in the past, when a cylindrical lens was switched in front of the subject's eye, there was a sense of discomfort due to the change in cylindrical power with a seam, as in the case of switching a spherical lens described above, and there was also the annoyance of the sound of switching the cylindrical lens. However, in this embodiment, by adjusting the desired cylindrical power using a Stokes lens, the cylindrical power changes seamlessly (without a seam), and furthermore, no switching sound is generated, thereby reducing the sense of discomfort and annoyance.

[0112] Furthermore, for example, the subjective ophthalmology device of this embodiment corrects the deviation in the spherical correction of the subject's eye, which deviation occurs when the first cylindrical lens and the second cylindrical lens are aligned with a composite axis angle, by placing a corrective optical element in front of the subject's eye. As a result, even when the cylindrical refractive power and astigmatic axis angle of the visual target light beam are changed with a Stokes lens to adjust the cylindrical correction and astigmatic axis correction of the subject's eye, the deviation in the spherical correction of the subject's eye is appropriately corrected by the corrective optical element, making it possible to accurately measure the ocular refractive power of the subject's eye.

[0113] Furthermore, for example, in the subjective ophthalmology device of this embodiment, the correction optical element for correcting the deviation in the spherical correction of the subject's eye is a variable-focus element (here, variable-focus lens 61) with a variable focal length, and the deviation in the spherical correction of the subject's eye is corrected by changing the spherical refractive power of the variable-focus element. For example, the deviation in the spherical correction caused by the first and second cylindrical lenses can change by a value smaller than the spacing (0.25D) between multiple spherical lenses in a conventional lens unit. Therefore, if a spherical optical element with a fixed focal length is used as the correction optical element, it may not be able to fully accommodate the deviation in the spherical correction. However, by using a variable-focus element with a variable focal length, it is possible to precisely accommodate the deviation in the spherical correction. As a result, the subject's eye can be appropriately corrected to the desired spherical correction.

[0114] Furthermore, for example, the subjective ophthalmology device of this embodiment acquires the add power of the subject's eye and switches between a first state in which the first cylindrical lens and the second cylindrical lens are aligned with a composite axis angle and a second state in which a corrective optical element based on the add power is arranged in the first state. That is, the subject's eye is corrected with a predetermined amount of spherical correction, cylindrical correction, and astigmatic axis correction, and the deviation of the spherical correction is corrected, and then the device switches between the first state in which no add power is added and the second state in which add power is added. This allows the optimal add power for the subject's eye to be measured with high accuracy.

[0115] Furthermore, for example, the subjective ophthalmology device of this embodiment uses both a corrective optical element for correcting deviations in the amount of spherical correction of the subject's eye and a corrective optical element for correcting the subject's eye with the amount of spherical correction, which makes it possible to easily adjust the amount of spherical correction for correcting the subject's eye, taking into account deviations in the amount of spherical correction of the subject's eye.

[0116] <Modifications> The subjective optometry device of this embodiment has been described with an example of a configuration in which the spherical power is adjusted by 0.25 D per step, but this is not limiting. For example, the subjective optometry device of this embodiment can continuously change the spherical power of the variable-focus lens 61. Therefore, the spherical power may be adjusted by a value smaller than 0.25 D per step (e.g., 0.10 D, 0.05 D, etc.). Similarly, the subjective optometry device of this embodiment has been described with an example of a configuration in which the cylindrical power is adjusted by 0.25 D per step, but this is not limiting. For example, the subjective optometry device of this embodiment can continuously change the cylindrical power of the Stokes lens 62. Therefore, the cylindrical power may be adjusted by a value smaller than 0.25 D per step (e.g., 0.10 D, 0.05 D, etc.).

[0117] The subjective ophthalmological examination device of this embodiment has been described with reference to an example in which the amount of spherical correction of the subject's eye E, the spherical refractive power of the variable-focus lens 61, and the arrangement of the first spherical lens 51 a and the second spherical lens 51 b are pre-associated. However, this is not limiting. For example, the subjective ophthalmological examination device of this embodiment may be configured to determine whether to arrange the first spherical lens 51 a and the second spherical lens 51 b based on the amount of spherical correction of the subject's eye E. In this case, the control unit 70 may determine whether to arrange the first spherical lens 51 a and the second spherical lens 51 b based on whether the amount of spherical correction of the subject's eye E exceeds a predetermined threshold. For example, the predetermined threshold may be a maximum or minimum value based on the range of spherical refractive power adjustable by the variable-focus lens 61.

[0118] In this way, the subjective ophthalmology 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 to be examined based on the amount of spherical correction of the eye to be examined (i.e., the modified spherical refractive power obtained by modifying the spherical refractive power of the visual target light beam), and switches and positions at least the optical elements based on the determination result. This makes it possible to easily determine, for example, a case where the amount of spherical correction of the eye to be examined is large and cannot be addressed by simply adjusting the spherical refractive power of the variable-focus element (here, the variable-focus lens 61), and to combine the variable-focus element and the optical element to accurately measure the ocular refractive power of the eye to be examined.

[0119] Furthermore, for example, the subjective ophthalmology device of this embodiment determines whether or not to place an optical element in front of the subject's eye based on the amount of spherical correction (the modified spherical refractive power of the visual target light beam) of the subject's eye and the range of refractive power of the corrective means. This allows the optical element to be appropriately positioned to accurately measure the ocular refractive power of the subject's eye when the variable optical element alone is not sufficient.

[0120] In the subjective optometry device of this embodiment, the initial correction amount of the subject's eye E or the correction amount switched to after the initial correction amount may be changed to a different correction amount during the distance vision test and near vision test described above. In this case, the control unit 70 may control either only the variable-focus element 61 or both the variable-focus element 61 and the first spherical lens 51a (or the second spherical lens 51b) depending on the amount of change between the two correction amounts. For example, the control unit 70 may control only the variable-focus element 61 if the amount of change between the two correction amounts does not exceed a predetermined amount. Alternatively, for example, the control unit 70 may control both the variable-focus element 61 and the first spherical lens 51a (or the second spherical lens 51b) if the amount of change between the two correction amounts exceeds a predetermined amount. For example, the amount of change between the two correction amounts may be preset, such as ±3.00D.

[0121] In this way, when the subjective ophthalmology device of this embodiment adjusts the spherical correction amount of the subject's eye (the modified spherical power obtained by changing the spherical power of the visual target light beam) from the first modified spherical power to the second modified spherical power different from the first modified spherical power, it controls only the first correcting means and changes the focal length of the variable-focus component in accordance with the amount of change between the first modified spherical power and the second modified spherical power. This makes it possible, for example, to easily adjust the spherical correction amount required for correction of the subject's eye and smoothly measure the ocular refractive power of the subject's eye.

[0122] The subjective ophthalmology device of this embodiment may be configured to determine a subjective value (e.g., a complete correction value) by controlling only the variable-focus component 61 after switching from the initial correction amount to a different correction amount for the subject's eye E. In this case, whether or not to place the first spherical lens 51a or the second spherical lens 51b in the examination window 43 may be set in advance depending on the initial correction amount for the subject's eye E. For example, if the initial correction amount for the subject's eye E is a spherical correction amount of −1.00 D, −1.00 D may be generated using only the variable-focus component 61 (spherical refractive power −5.00 D to +5.00 D). Alternatively, if the initial correction amount for the subject's eye E is a spherical correction amount of −4.50 D, −4.5 D may be generated by combining the variable-focus component 61 and the first spherical lens 51a (spherical refractive power −10.00 D). For example, the amount of change until the initial correction amount of the subject's eye E is adjusted to the final correction amount (i.e., the difference between the initial correction amount and the final correction amount) can be roughly determined through experiments, simulations, etc. Therefore, by previously positioning the first spherical lens 51a according to the initial correction amount of the subject's eye E, it is not necessary to rotate the second auxiliary lens disk 50b during measurement of the subject's eye E, and a more seamless response is possible. Note that when using such a configuration, multiple spherical lenses may be provided, and their spherical refractive powers may be changed in predetermined steps (for example, in 3.00D increments).

[0123] REFERENCE SIGNS LIST 1 Housing 2 Presentation window 10 Examiner controller 30 Light projection optical system 40 Eye refractive power measurement unit 43 Examination window 60 Control unit 100 Subjective ophthalmological 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, Control means for controlling the corrective means, Equipped with, The correction means includes a first correction means for changing the spherical refractive power of the target light beam using a variable focal length member, and a second correction means for changing the spherical refractive power of the target light beam by switching and arranging optical members. The subjective eye examination device is characterized in that the control means controls the first corrective means and the second corrective means and performs a change in the spherical refractive power of the target light beam.

2. In the subjective eye examination device of claim 1, 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, The control means controls at least the second corrective means and switches and arranges the optical members when the modified spherical refractive power obtained by changing the spherical refractive power of the target light beam exceeds the range of the first refractive power in the first corrective means.

3. In the subjective eye examination device of claim 2, The system includes a determination means for determining whether or not to arrange the optical member based on the modified spherical refractive power of the target light beam, The control means controls at least the second corrective means and switches and arranges the optical members based on the determination result of the determination means, characterized in that it is a subjective eye examination device.

4. In the subjective eye examination device of claim 1, A subjective optometry device characterized in that 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.

5. In a subjective ophthalmoscopic device according to any one of claims 1 to 4, The control means is characterized in that, when adjusting 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 controls only the first corrective 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, thereby changing the focal length of the variable focal member.

6. A corrective means positioned in front of the eye of a subject and for changing the optical properties of a target light beam emitted from a target presentation means, comprising: a first corrective means for changing the spherical refractive power of the target light beam using a variable focal length member; and a second corrective means for changing the spherical refractive power of the target light beam by switching and arranging optical members, 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, The subjective optometry device is made to perform a control step that controls the corrective means. The control step is characterized by controlling the first corrective means and the second corrective means to change the spherical refractive power of the target light beam, and is a subjective optometry program.