Optometer and control program for optometer

Abstract

To make it possible to efficiently and easily perform subjective examination of optical characteristics of the eye to be tested.SOLUTION: An optometer for presenting the eye to be tested with an optotype and subjectively performing optical characteristics of the eye to be tested includes: a correction optical system having a variable lens capable of electrically varying the correction degree and a variable prism capable of varying an amount of prism electrically; and control means. The control means presents an optotype CH presented via the correction optical system with varying correction degrees and at different places so that it is virtually simultaneously visible to the eye to be tested by performing control by synchronizing a change of the correction degree of the variable lens and a change of a prism amount of the variable prism.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to an optometry apparatus and a control program for the optometry apparatus that subjectively examines the optical characteristics of a subject's eye. [Background technology]

[0002] There is known an optometry device that subjectively tests the optical characteristics of a subject's eye by placing a corrective optical system in front of the subject's eye and presenting a visual target to the subject's eye through an optical element of the corrective optical system (e.g., a spherical lens, a cylindrical lens, etc.) (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-149843 Summary of the Invention [Problem to be solved by the invention]

[0004] In subjective examinations using optometry devices, the correction power of a corrective optical system placed in front of the subject's eye is changed, and the subject is asked to check how well the optotype appears under various correction conditions, thereby testing the optical characteristics of the subject's eye. However, with conventional optometry devices, the test is conducted by comparing how well the optotype appears before and after the correction power is changed, making it difficult for the subject to compare the difference in how well the optotype appears, and the test often takes a long time as the subject may have to change the correction power multiple times.

[0005] In view of the above-described conventional techniques, the present disclosure has as its technical object to provide an optometry apparatus and a control program for the optometry apparatus that can efficiently and easily perform a subjective test of the optical characteristics of a subject's eye. [Means for solving the problem]

[0006] (1) An optometry device provided by a typical embodiment of the present disclosure is an optometry device that presents a visual target to the eye to be examined and subjectively examines the optical characteristics of the eye, and is equipped with a corrective optical system having a variable lens that can electrically change the correction power and a variable prism that can electrically change the prism amount, and a control means, wherein the control means controls the change in the correction power of the variable lens and the change in the prism amount of the variable prism in synchronization with each other, thereby presenting the visual target presented via the corrective optical system at different correction powers and at different positions so that it can be seen by the eye to be examined substantially simultaneously. (2) A control program for an optometry device provided by a typical embodiment of the present disclosure is an optometry device that presents a visual target to the eye to be examined and subjectively examines the optical characteristics of the eye, and is a control program for an optometry device that is equipped with a corrective optical system having a variable lens that can electrically change the correction power and a variable prism that can electrically change the prism amount, and is characterized in that, when executed by a control unit of the optometry device, the control program causes the optometry device to execute a control step of presenting the visual target presented via the corrective optical system at different correction powers and different positions so that it is visible to the eye to be examined substantially simultaneously by controlling in synchronization the change in the correction power of the variable lens and the change in the prism amount of the variable prism. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an external view of the overall configuration of an optometric apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a schematic configuration of a correction optical system arranged in the left lens unit. [Figure 3] FIG. 2 is a diagram illustrating the configuration of a target presenting unit 200. [Figure 4] FIG. 2 is a diagram showing a control system of the optometry apparatus. [Figure 5] FIG. 10 is a diagram illustrating an example of an optometry program. [Figure 6] 10A and 10B are diagrams illustrating the presentation of optotypes with different correction powers and at different positions that are visible to the subject's eye substantially simultaneously in a comparison mode. [Figure 7]10A and 10B are diagrams illustrating control for repeatedly switching between the first presentation state and the second presentation state at high speed. [Figure 8] FIG. 10 is a diagram showing an example of information displayed on the monitor screen in a comparison mode. [Figure 9] FIG. 1 is a diagram illustrating the presentation position of the target when switching between four presentation states. [Figure 10] FIG. 10 is a diagram illustrating control for repeatedly switching between four presentation states at high speed. [Figure 11] 10A and 10B are diagrams illustrating changes in the prism amount of a variable prism according to the size of a target. [Figure 12] 10A and 10B are diagrams illustrating an example in which a variable-focus lens capable of changing the correction power for astigmatism is added to a correction optical system. [Figure 13] 10A and 10B are diagrams showing an example in which point cloud targets are presented at different positions in the astigmatic axis examination step. [Figure 14] FIG. 10 is a diagram illustrating an example of simultaneous presentation of near and far targets. DETAILED DESCRIPTION OF THE INVENTION

[0008] [overview] Hereinafter, one exemplary embodiment will be described with reference to the drawings. Note that the items grouped in <> below can be used independently or in conjunction with each other.

[0009] For example, an optometry apparatus according to the present disclosure (e.g., optometry apparatus 1) includes a corrective optical system (e.g., corrective optical system 120) having a variable lens (e.g., variable-focus lens 124) and a variable prism (e.g., variable prism 122), and control means (e.g., control unit 50, control unit 150). For example, the optometry apparatus is used to present a visual target to the subject's eye and subjectively test the optical characteristics of the subject's eye. For example, the variable lens may be an optical element whose correction power can be electrically changed. For example, the variable prism may be an optical element whose prism amount can be electrically changed. The variable lens may be a variable-focus lens whose focal length can be changed. The variable lens may also include at least one of a first variable-focus lens whose spherical correction power can be changed and a second variable-focus lens whose astigmatism correction power can be changed.

[0010] For example, the control means controls the variable lens and the variable prism. For example, the control means synchronizes and controls the change in the corrective power of the variable lens and the change in the prism amount of the variable prism, so that the optotypes presented to the subject's eye via the corrective optical system are presented with different corrective powers and at substantially different positions so that they are visible to the subject's eye substantially simultaneously. This shortens the examination time and enables the subjective examination to be performed efficiently and easily. Note that the synchronization between the change in the corrective power of the variable lens and the change in the prism amount of the variable prism may be approximately synchronized (a state in which the subject feels that the two are synchronized).

[0011] The different positions of the optotypes presented to the subject's eye so that they can be seen substantially simultaneously are positions perpendicular to the optometry optical axis (e.g., the optometry optical axis LS1) of the corrective optical system. The different positions of the optotypes may be positions at which the optotypes are seen separately without overlapping. The optotypes presented to the subject's eye via the corrective optical system may be presented on a single screen. In this case, the optotype may be displayed on a display screen, projected onto a single screen by an optotype projector, or may be a paper optotype. The presenting method of the optotype is not important. The optometry device disclosed herein does not require synchronization control with a variable lens when presenting the optotype, thereby increasing the flexibility of the optotype presenting device. Furthermore, various optotype presentation methods can be combined.

[0012] For example, the control means may be capable of switching between at least two presentation states: a first presentation state in which a visual target is presented at a first position by a first prism amount of the variable prism with a first corrective power of the variable lens; and a second presentation state in which a visual target is presented at a second position by a second prism amount of the variable prism with a second corrective power of the variable lens. By repeating this switching, the visual target in at least two presentation states may be presented to the subject's eye substantially simultaneously. In this case, for example, the control means may control the repetition time of switching between the at least two presentation states based on the time it takes for an afterimage to remain in the subject's eye. Furthermore, the control means may set the presentation time of the visual target in each presentation state to be relatively longer than the switching time of each presentation state. This allows the subject's eye to view the same visual target at different positions substantially simultaneously without perceiving the switching between the presentation states. For example, the repetition time of switching may be 1 / 30 seconds or less.

[0013] For example, the optometry apparatus may include an information acquisition unit (e.g., control unit 50, control unit 150) that acquires size information of a target presented to the subject's eye. In this case, for example, the control unit changes the prism amount of the variable prism based on the acquired size information of the target. This allows the subject to distinguish between targets in different presentation states and appropriately compare how the targets appear. For example, the control unit may change the prism amount of the variable prism by a larger amount as the target size increases. For example, the control unit may determine the prism amount of the variable prism for each presentation state so that the targets presented in each presentation state appear separate and do not overlap. Furthermore, when the target size is smaller than a predetermined size, the control unit may determine the prism amount of the variable prism so that the spacing between the targets in each presentation state is not too narrow or so that the targets in each presentation state are separated by an appropriate distance.

[0014] For example, the optometry apparatus may include a transmitter (e.g., the control unit 50) that transmits a selection signal for the optotype to an optotype presenting unit (e.g., the optotype presenting unit 200) that presents the optotype. For example, the information acquiring means may include a storage means (e.g., the storage unit 330) that stores size information for the optotype. In this case, the control means may change the prism amount of the variable prism based on the size information for the optotype acquired for each optotype selected by the selection signal for the optotype.

[0015] The optometry device may also include a notification means (e.g., the monitor 310) that notifies the examiner of optometry information. For example, the notification means notifies information related to the correction power of the variable lens in each presentation state and information related to the presentation position of the optotype in each presentation state. For example, the optometry device may include a monitor that displays optometry information on a screen, and this monitor may be used as the notification means. For example, the notification means may be a sound generating device that notifies the optometry information by sound.

[0016] It should be noted that the present disclosure is not limited to the devices described in the present embodiment. For example, a control program (software) for an optometry device that performs the functions of the following embodiments may be supplied to a system or device via a network or various storage media. The control device (e.g., a CPU) of the system or device may then read and execute the program.

[0017] For example, the control program of the optometric device is executed by the control unit of the optometric device, causing the optometric device to execute a control step of presenting an optotype presented via the corrective optical system at different corrective powers and at different positions so that it can be seen by the examined eye substantially simultaneously by synchronizing and controlling the change in the corrective power of the variable lens and the change in the prism amount of the variable prism.

[0018] [Example] <Overall structure> An example of this embodiment will be described with reference to the drawings. Fig. 1 is an external view of the overall configuration of an optometry apparatus 1 according to this example. The optometry apparatus 1 includes a measurement unit 100, an optotype presenting unit 200, an optometry controller 300, and the like. The measurement unit 100, the optotype presenting unit 200, and the controller 300 are connected to each other by wire or wirelessly.

[0019] 1, a holding arm 280 is attached to the upper part of the housing 202 of the optotype presenting unit 200. The holding arm 280 holds the measurement unit 100 so that it is positioned at a predetermined position. For example, the holding arm 280 holds the measurement unit 100 in a switchable manner between at least one of a testing position in which the measurement unit 100 is lowered to the front of the housing 202 and a standby position in which the measurement unit 100 is raised to the top of the housing 202.

[0020] <Measurement unit> The measurement unit 100 includes a lens unit 110, a moving unit 140, a forehead rest 142, etc. The lens unit 110 has a pair of left and right lens units, a left lens unit 110L and a right lens unit 110R. The moving unit 140 is held by a holding arm 280. The moving unit 140 also holds the left lens unit 110L and the right lens unit 110R so that they can each move in the left-right direction (X direction).

[0021] The left and right lens units 110 each have an examination window 112. The lens unit 110 also has a clear examination window (not shown) on the side opposite to the subject side. The left and right lens units 110 each have a correction optical system 120.

[0022] 2 is a diagram illustrating a schematic configuration of the corrective optical system 120 disposed in the left lens unit 110L. The subject's eye observes a visual target presented by the visual target presenting unit 200 via the corrective optical system 120 on an examination optical axis LS1 passing through the examination window 112. The corrective optical system 120 includes, on the examination optical axis LS1, a variable prism 122, a variable-focus lens 124 which is an example of a variable lens, an astigmatism lens 126, an auxiliary lens 128, and the like.

[0023] The variable prism 122 is an optical element whose prism amount can be electrically changed, and the prism amount can be continuously changed by the driver 122A. The prism direction of the variable prism 122 can be arbitrarily changed by the driver 122A. For example, the variable prism 122 is a liquid lens whose prism amount can be changed by applying a voltage. The variable prism 122 may be any optical element whose prism amount can be electrically changed and whose prism direction can be changed in at least two directions, left / right or up / down, and may be used in combination with a method of rotating the prism.

[0024] The variable-focus lens 124 is an optical element whose spherical correction power (here, focal length) can be electrically changed, and the correction power (focal length) can be continuously changed by the driving unit 124A. For example, the variable-focus lens 124 is a liquid lens whose focal length can be changed by applying a voltage. The variable-focus lens 124 may be any optical element whose correction power can be electrically changed, and may be a liquid crystal lens or an Alvarez lens.

[0025] In this embodiment, the astigmatism lens 126 is composed of multiple astigmatism lenses 126 with different astigmatism powers. The multiple astigmatism lenses 126 are arranged on the same circumference of a lens disk 126B. The lens disk 126B is rotated by the driving unit 126A, thereby switching and positioning the astigmatism lens 126 with the desired power on the examination optical axis LS1. The astigmatism lenses 126 on the examination optical axis LS1 are configured to be rotatable around the examination optical axis LS1, and the astigmatism axis angle is changed by rotating the astigmatism lenses 126 by the driving unit 126A. If there are a large number of astigmatism lenses 126 for switching the astigmatism power, multiple lens disks 126B may be used. Alternatively, the astigmatism lens 126 may be composed of a so-called Stokes astigmatism lens, in which the astigmatism power is continuously changed using two cylindrical lenses with the same absolute value.

[0026] The auxiliary lens 128 has a plurality of auxiliary lenses arranged on the same circumference of a lens disk 128B. For example, the plurality of auxiliary lenses 128 include a shielding plate, a polarizing filter, a red filter, a green filter, a cross cylinder lens, etc. The lens disk 128B is rotated by the driving unit 128A, so that the desired auxiliary lens 128 is switched and positioned on the ophthalmic optical axis LS1.

[0027] <Optical target presentation unit> 3 is a diagram illustrating the configuration of the optotype presenting unit 200. The optotype presenting unit 200 includes a projection optical system 210 inside a housing 202. A presentation window 204 is provided on the front side of the housing 202. The presentation window 204 is a window for presenting an optotype to the subject's eye. The presentation window 204 transmits the optotype light beam in the projection optical system 210 and projects the optotype light beam that has passed through the presentation window 204 onto the subject's eye.

[0028] The projection optical system 210 includes a display 212, a half mirror 214, a concave mirror 316, an image sensor 165, etc. The display 212 displays a visual target (e.g., a fixation target, a test visual target, etc.). The visual target light beam emitted from the display 212 travels along an optical axis L1, is reflected by the half mirror 214, and travels toward the concave mirror 316 along an optical axis L2. The visual target light beam reflected by the concave mirror 316 travels again toward the half mirror 214 along an optical axis L3. The visual target light beam reflected by the half mirror 214 travels along an optical axis L4 and is guided to the subject's eye via the presentation window 204 and the optical system of the measurement unit 100. That is, the subject's eye observes the visual target presented in the direction of the optical axis L4.

[0029] For example, the focal length of the concave mirror 316 is designed so that the optical distance from the display 212 to the subject's eye is 5 m. This allows the optotype presenting unit 200 to be used as a space-saving optotype presenting device capable of presenting an optotype for distance vision. Furthermore, the display 212 is moved by the drive unit 213 and placed on the optical axis L3, thereby presenting an optotype for near vision to the subject's eye. Note that instead of the concave mirror 316, an aspherical mirror, a free-form mirror, a lens, or the like may be used to guide the optotype light beam from the display 212 to the half mirror 214.

[0030] <controller> 1, the controller 300 includes a monitor 310 and an operation unit 320. The monitor 310 displays information on various test items for subjective ocular refractive power, information on optotypes presented by the optotype presenting unit 200, and the like. The operation unit 320 includes various switches for proceeding with the eye examination, switches for inputting data, switches for selecting optotypes presented by the optotype presenting unit 200 (optotypes displayed on the display 212), switches for inputting signals for driving each driving unit (the measurement unit 100, each driving unit provided in the optotype presenting unit 200), and the like. The monitor 310 may be a touch panel, and may also function as the operation unit 320. The monitor 310 also functions as a notification unit for notifying the examiner of the eye examination information by displaying the eye examination information on the screen.

[0031] <Control system> Fig. 4 is a diagram showing the control system of the optometry apparatus 1. In Fig. 4, a control unit 150 provided in the measurement unit 100 is connected to and controls each driving unit of the measurement unit 100. A control unit 250 provided in the optotype presenting unit 200 is connected to and controls the driving of a display 212 and a driving unit 213.

[0032] The control unit 50 included in the controller 300 is connected to a monitor 310, an operation unit 320, and a memory unit 330. The control unit 50 controls the monitor 310 and receives operation signals from the operation unit 320. The control unit 50 is also communicatively connected to the control unit 150 of the measurement unit 100 and the control unit 250 of the optotype presenting unit 200 via wired or wireless communication, and also serves as a transmission unit that transmits command signals for driving each component (e.g., an optotype selection signal, a signal for switching the lenses of the corrective optical system 120, etc.) to the control units 150 and 250. In other words, the control unit 50 controls the overall operation of the optometry apparatus 1.

[0033] The control unit 50, the control unit 150, and the control unit 250 are configured with a general CPU, RAM, ROM, etc. The storage unit 330 stores a control program for controlling the operation of the optometry apparatus 1, an optometry program for the examination procedure, and optotype size information of the optotype presented by the optotype presenting unit 200. The storage unit 330 also stores the examination results.

[0034] The control unit 50 is also connected to an external objective refraction measurement device 70 via a data server 60 or directly. Information on the eye refractive power (spherical power, astigmatic power, astigmatic axis angle), interpupillary distance information, etc., of the subject's eye objectively obtained by the objective refraction measurement device 70 are acquired by the control unit 50, which also serves as information acquisition means. Generally, objective eye refractive power information obtained by the objective refraction measurement device 70 is refractive error information relative to emmetropia, and will be treated as such in this embodiment as well.

[0035] <Operation> The operation of the optometry apparatus 1 having the above-described configuration will be described. For example, when subjective optical characteristics are examined using the optometry apparatus 1, objective value data, which is ocular refractive power information of the subject's eye obtained in advance by the objective ocular refractive power measurement device 70, is input via the data server 60 and stored in the storage unit 330. Furthermore, if the subject wears eyeglasses, lens information (spherical power, astigmatic power, and astigmatic axis angle) of the eyeglass lenses is input by operating the operation unit 320 or the like and stored in the storage unit 330.

[0036] At the start of the examination, the subject places his / her forehead against the forehead rest 142, and the left and right measurement units 100 are moved left and right based on the subject's interpupillary distance, and the left and right eyes to be examined are positioned at the center of the eye examination window 112, thereby aligning the eyes to a predetermined positional relationship with the corrective optical system 120.

[0037] Once the alignment of the subject's eye is complete, the examiner begins the subjective examination. Here, an example will be described in which an optometry program in which the examination procedure is programmed is executed. The optometry program is stored in the memory unit 330. When the optometry program start switch on the operation unit 320 is pressed, the optometry program starts. Figure 5 shows an example of the optometry program.

[0038] For example, by pressing the advance switch of the operation unit 320, the eye examination program proceeds to each examination step in the following order: naked eye visual acuity test step S1, spectacle visual acuity test step S2, objective value confirmation test step S3, first red-green test step S4, astigmatism axis test step S5, astigmatism power test step S6, second red-green test step S7, best visual acuity confirmation test step S8, binocular balance test step S9, and power adjustment test step S10. In each of the examination steps S1 to S10, an optical element of the corrective optical system 120 corresponding to the examination step is placed in the left and right eye examination windows 132, and a predetermined optotype is presented by the optotype presenting unit 200.

[0039] In the objective value confirmation test step S3, the corrective optical system 129 is initially set based on the objective value data, and a visual acuity value optotype is presented by the optotype presentation unit 200, and the visual acuity based on the objective value data is confirmed. In the first red-green test step S4, the spherical power is adjusted to place the circle of least confusion at the retina for astigmatism testing using a cross-cylinder lens. In the second red-green test step S7, the spherical power is adjusted to prevent overcorrection. In the best visual acuity confirmation test step S8, the fully corrected power for one eye is obtained. The spherical power is changed and compared to how the distance test optotype appears, and the spherical power is adjusted to the most positive value that achieves the best visual acuity. Note that the first red-green test step S4 through the second red-green test step S7 first test the right eye, and then move on to testing the left eye.

[0040] For example, in the best visual acuity confirmation test step S8, in a conventional device, the subject's vision of a target in a first state with a first spherical correction power is compared with that in a second state with a second correction power obtained by changing the spherical power from the first correction power. After showing the target in the first state with the first correction power, the subject switches to the second state by operating the switch on the operation unit 320, and is asked to respond to which state looks better and whether there is any difference in the vision. In this case, the subject memorizes the vision of the target in the first state and compares it with the vision of the target when switched to the second state. However, if the difference in vision between the two states is subtle, switching between the first and second states may be required multiple times. This can result in a time-consuming test and a burden on the subject. Furthermore, comparing vision based on memory can be time-consuming, especially for elderly subjects.

[0041] Therefore, in the examination step of the present disclosure, in which the appearance of the optotype is compared while changing the corrective power, a comparison mode is used. When the comparison mode is set by the switch on the operation unit 320, the variable prism 122 is used, and control is performed to synchronize (or even approximately synchronize) the change in the corrective power of the variable-focus lens 124 with the change in the prism amount of the variable prism 122. This control allows the optotype presented on one screen by the optotype presenting unit 200 to be presented with different corrective powers and at different positions (different positions in a direction perpendicular to the eye examination optical axis LS1) so that they are visible to the eye to be examined substantially simultaneously. At this time, the presenting state is switched to at least two states: a first presentation state ST1 in which the optotype is presented at a first position using a first corrective power of the variable-focus lens 124 and a first prism amount of the variable prism 122; and a second presentation state ST2 in which the optotype is presented at a second position using a second corrective power of the variable-focus lens 124 and a second prism amount of the variable prism 122. By repeating this switching, at least two optotypes in different presentation states are presented to the subject's eye substantially simultaneously. This allows the subject to easily respond to which one looks better by comparing the appearance of the optotypes that are visible simultaneously, without relying on memory. This allows the test to be conducted efficiently and without taking much time.

[0042] The control of the variable prism 122 and the variable-focus lens 124 in this comparison mode will be described in detail below. For example, suppose that in the second red-green test step S7, the subjective correction power of the eye to be tested (e.g., the right eye) is a spherical power S of -3.0D (diopters) and an astigmatism power C of 0D. In the comparison mode test in best visual acuity confirmation test step S8, suppose that a vertical row of optotypes CH representing the visual acuity value (e.g., visual acuity value 1.0) at which the best visual acuity is obtained is presented by the optotype presenting unit 200, as shown in FIG. 6(a). In FIG. 6(a), the optotype CH is presented at a central position M0 in the left-right direction based on the test optical axis LS1.

[0043] 6(b), first, as a first presentation state ST1, the variable-focus lens 124 is controlled so that the spherical power S of the first corrective power is −3.0 D. In synchronization with this control, the variable prism 122 is controlled based on the optotype size (visual acuity value) of the optotype CH, so that, for example, the optotype direction (the direction in which the optotype is visible to the test eye) LSa1 is shifted leftward by the prism amount ΔP1 with respect to the front direction of the test optical axis LS1, and the optotype CH is presented at a position M1 shifted to the left in the direction perpendicular to the test optical axis LS1.

[0044] 6(c), in a second presentation state ST2, the variable-focus lens 124 is controlled so that the spherical power S (correction power) is changed by one step (0.25D) to the positive side relative to the first correction power (spherical power S -3.0D) to -2.75D. In synchronization with this control, the variable prism 122 is controlled based on the size of the optotype CH, and, contrary to the first presentation state ST1, for example, the optotype direction LSa2 is shifted rightward by a prism amount ΔP2 relative to the front direction of the test optical axis LS1, and the optotype CH is presented at a position M2 shifted to the right in the direction perpendicular to the test optical axis LS1.

[0045] Then, the control unit 150 automatically and repeatedly switches between the first presentation state ST1 of Fig. 6(b) and the second presentation state ST2 of Fig. 6(c) at high speed, so that the optotype CH at the position M1 presented in the first presentation state ST1 and the optotype CH at the position M2 presented in the second presentation state ST2 are presented to the eye to be examined so as to be viewed substantially simultaneously, as shown in Fig. 6(d). In other words, the first presentation state ST1 corrected by the first correction amount and the second presentation state ST2 corrected by the second correction amount are alternately and repeatedly switched at high speed, so that the eye to be examined sees the same optotype CH in different correction power states and at different positions (different positions in the direction perpendicular to the eye examination optical axis LS1) substantially simultaneously, and the subject can compare how they look.

[0046] 7 is a diagram illustrating control for rapidly repeating switching between the first presentation state ST1 and the second presentation state ST2. The presentation time of the target in the first presentation state ST1 (the stop time of switching) is defined as ta1, and the presentation time of the target in the second presentation state ST2 (the stop time of switching) is defined as ta2. The switching time from the first presentation state ST1 to the second presentation state ST2 is defined as tc1, and the switching time from the second presentation state ST2 to the first presentation state ST1 is defined as tc2. The repetition time of one cycle from the start of the first presentation state ST1 to the switching time tc2 after the second presentation state ST2 is defined as RPt.

[0047] Here, the repetition time RPt is the time during which an afterimage remains in the eye (the time during which the image change is not perceived). For example, the repetition time RPt is set to 1 / 30 seconds (33 msec) or less. The presentation times ta1 and ta2 are set relatively longer than the switching times tc1 and tc2. The presentation times ta1 and ta2 are preferably set to be the same. The switching times tc1 and tc2 may also be set to be the same. By repeatedly switching between the first presentation state ST1 and the second presentation state ST2 at the repetition time RPt, the same optotype can be presented to the subject's eye at different positions substantially simultaneously. This allows the subject to easily compare how it appears.

[0048] 8 is a diagram showing an example of information displayed on the screen of the monitor 310 in the comparison mode. The display unit 410 in the upper left of the screen displays subjective value data for both the left and right eyes. The display unit 412 below it displays the design CHa of the optotype CH presented by the optotype presentation unit 200. The display unit 420 on the right side of the screen displays information related to the corrective power of the variable-focus lens 124 in each presentation state, information related to the presentation position of the optotype CH changed by the variable prism 122 in each presentation state, and the like, and notifies the examiner. Here, by controlling the variable prism 122, the optotype CH in the first presentation state ST1 appears to the examinee to be positioned on the left and the optotype CH in the second presentation state ST2 appears to the examinee to be positioned on the right, so the optotype presentation position display unit 422 displays the optotype design CHa side by side. Corresponding to the arrangement of the optotype patterns CHa, the correction power switching display unit 424 displays the correction power (S-3.00) for the first presentation state ST1 and the correction power (S-3.00) for the second presentation state ST2, which are switched by the variable-focus lens 124. These displays allow the examiner to know the switching status of each presentation state (e.g., the correction power in each presentation state, the presentation position of the optotype in each presentation state), and to take appropriate measures in response to the examinee's response to how the optotype appears. Note that the screen of the monitor 310 displays a list of selectable optotypes, displays switches to be operated in each test, etc., but these displays are omitted in FIG. 8. The display unit 420 may be displayed as a pop-up.

[0049] In the comparison mode test, the subject is asked to indicate which of the optotypes CH at the presentation position M1 in the first presentation state ST1 and the optotype CH at the presentation position M2 in the second presentation state ST2 is more clearly visible. If the subject responds that the optotype CH at the presentation position M1 in the first presentation state ST1, which has a stronger correction power, is more clearly visible, the fully corrected power of the subject's eye is determined to be the corrected power of the first presentation state ST1. If the subject responds that the optotypes CH at the presentation positions M1 and M2 are similarly visible, the fully corrected power of the subject's eye is determined to be a more positive power, and the corrected power of the second presentation state ST2 is selected as a candidate. In this case, a more positive power may be acceptable. Therefore, if an operation signal to lower the corrected power by one level is input via the operation unit 320, the first presentation state ST1 is replaced with the third presentation state ST3, for example. In the third presentation state ST3, the variable-focus lens 124 is controlled to change the second corrective power (S-2.75D) in the second presentation state ST2 by one step (0.25D) to S-2.50D. As in the first presentation state ST1, the variable prism 122 is controlled in synchronization with the variable-focus lens 124 to present the optotype CH in a different target direction (which may be the same as the optotype direction LSa1) from the target direction LSa2 in the second presentation state ST2. That is, in the third presentation state ST3, the optotype CH is presented at a different position from that in the second presentation state ST2. Then, by automatically and repeatedly switching between the second presentation state ST2 and the third presentation state ST3 at high speed, the optotype CH at different positions is presented to the subject's eye so that they appear to be viewed substantially simultaneously.

[0050] The subject is asked to indicate which of the optotypes CH at the presentation position M2 in the second presentation state ST2 and the optotype CH at the presentation position (M1) in the third presentation state ST3 is better. If the subject responds that the optotype CH in the second presentation state ST2, which has a stronger correction power, is better, the fully corrected power of the subject's eye is determined to be the corrected power of the second presentation state ST2. If the subject responds that the optotype CH presented in the second presentation state ST2 and the optotype CH presented in the third presentation state ST3 are similarly visible, the fully corrected power of the subject's eye is set to a more positive power, and the corrected power of the third presentation state ST3 is selected as the candidate. In this case, if an operation signal to lower the corrected power by one level is input from the operation unit 320, the corrected power of the second presentation state ST2 is replaced with the corrected power of the fourth presentation state ST4, which is one level more positive than the corrected power of the third presentation state ST3. Then, the appearance of the target CH in the third presentation state ST3 and the fourth presentation state ST4 are compared again, and the most positive correction power that results in the same appearance is determined as the perfect correction power of the eye to be examined.

[0051] In the above, the variable prism 122 and the variable focus lens 124 are controlled to two presentation states (first presentation state ST1 and second presentation state ST2, second presentation state ST2 and third presentation state ST3, etc.), but they may also be controlled to three or more presentation states.

[0052] For example, assume that the display is switched to four presentation states: a first presentation state ST1, a second presentation state ST2, a third presentation state ST3, and a fourth presentation state ST4. The spherical correction power controlled by the variable-focus lens 124 is changed in the positive direction by one step (0.25D) from the correction power in the first presentation state ST1 in the second presentation state ST2, the third presentation state ST3, and the fourth presentation state ST4, in that order. The prism amount of the variable prism 122 is controlled so that the presentation positions of the optotype CH when switching between the four presentation states are Mb1, Mb2, Mb3, and Mb4, from left to right, as shown in FIG. 9 . The change in prism amount is determined based on the size of the optotype CH, so that the optotype CH at each position is in the optotype directions LSb1, LSb2, LSb3, and LSb4, so that the optotype CH at each position does not overlap.

[0053] During the comparison mode test, the control unit 150 switches the first presentation state ST1, the second presentation state ST2, the third presentation state ST3, and the fourth presentation state ST4 in sequence at high speed, and this is automatically repeated. For example, as shown in Fig. 10, the presentation times of the first presentation state ST1, the second presentation state ST2, the third presentation state ST3, and the fourth presentation state ST4 are set to ta1, ta2, ta3, and ta4, respectively, and the switching of each presentation time is controlled by switching times tc1, tc2, tc3, and tc4, which are relatively shorter than the presentation times ta1, ta2, ta3, and ta4. The repetition time RPt of one cycle from the start of the first presentation state ST1 to the switching time tc4 after the fourth presentation state ST4 is set to a time (e.g., 1 / 30 seconds or less) that makes it difficult to perceive the image switching due to afterimages in the eye, as in Fig. 7. As a result, the same target CH is presented to the subject's eye so that it can be seen simultaneously at four different positions Mb1, Mb2, Mb3, and Mb4 with different correction powers.

[0054] The subject is asked to respond to which of the four positions Mb1, Mb2, Mb3, and Mb4 the optotype CH looks best. The corrected power for the most positive presentation state is determined as the perfect correction power for the optotype CH position that looks similar. In this way, by making it possible to simultaneously compare optotype CHs in three or more presentation states, the test time can be further shortened and the test can be performed more efficiently.

[0055] Although the above describes an example in which the comparison mode is applied in the best visual acuity confirmation test step S8, this is not limiting. The comparison mode test of the present disclosure, in which the corrective power is changed and the appearance of the optotype is compared, may also be applied to the binocular balance test step S9, the power adjustment test step S10, the first red-green test step S4, the second red-green test step S7, etc. In the red-green test step, a red-green optotype is presented by the optotype presentation unit 200. In the case of a binocular test, the change in the corrective power of the variable-focus lens 124 and the change in the prism amount of the variable prism 122 are performed at the same time for both the left and right eyes.

[0056] Furthermore, if an add power test is performed after the distance power adjustment test step S10, the comparison mode test of the present disclosure may also be applied to this test. In the add power test, the control unit 250 of the optotype presenting unit 200 drives the drive unit 213, and the display 212 is placed on the optical axis L3, thereby presenting an optotype for near vision to the subject's eye.

[0057] <Changes in the prism amount of the variable prism according to the size of the target> In the above description, it is preferable that the change in the prism amount of the variable prism 122 be controlled according to the size of the optotype CH presented in the optotype presentation unit 200. In this case, the control unit 50 acquires size information of the optotypes presented in the optotype presentation unit 200. For example, the size information of the optotypes presented in the optotype presentation unit 200 is stored in the storage unit 330. Based on an optotype selection signal (including an optotype switching signal) from the operation unit 320, the control unit 50 reads and acquires size information for each selected optotype from the storage unit 330. For example, as the size of the optotype increases, the prism amount of the variable prism 122 also changes significantly.

[0058] 11A and 11B are diagrams illustrating changes in the prism amount of the variable prism 122 according to the size of the optotype CH. The optotype CH shown in Fig. 11A has a lower visual acuity value (for example, a visual acuity value of 0.2) than the optotype CH shown in Fig. 6A. Therefore, the optotype size Cw of the optotype CH is larger than the optotype size of the optotype CH in Fig. 6A. The prism amount of the variable prism 122 is determined based on the optotype size Cw of the optotype CH so that the optotypes CH presented in each presentation state do not overlap and appear separate.

[0059] For example, when control is performed in two presentation states, a first presentation state ST1 and a second presentation state ST2, as in the case of Fig. 6, the prism amount corresponding to the target direction LSc1 in the first presentation state ST1 and the prism amount corresponding to the target direction LSc2 in the second presentation state ST2 are determined and the variable prism 122 is controlled so that the target CH presented at the left position Mc1 in the first presentation state ST1 and the target CH presented at the right position Mc2 in the second presentation state ST2 are separated without overlapping, as shown in Fig. 11(b). This allows the subject to distinguish between the targets in the different presentation states and appropriately compare how the targets appear.

[0060] Furthermore, when the optotype size Cw is smaller than a predetermined size (for example, the size of an optotype for a visual acuity value of 0.7) (in other words, in the case of an optotype with a visual acuity value higher than the expected visual acuity value), the prism amount of the variable prism 122 may be determined so that the intervals between the optotypes CH in each presentation state do not become too narrow. For example, for optotypes with a size equal to or smaller than a predetermined optotype size, the prism amount of the variable prism 122 may be determined so that the intervals between the optotypes in each presentation state are constant. This allows the subject to identify and view each optotype in different presentation states even in the case of small-sized optotypes, and to appropriately compare how the optotypes appear.

[0061] <Application of variable focus lenses for astigmatism> In the above description, an example was described in which the correction optical system 120 is provided with a variable-focus lens 124 as a variable lens, the spherical correction power of which can be changed, but it may also be provided with a variable-focus lens that is capable of changing the correction power of astigmatism.

[0062] Fig. 12 is a diagram illustrating an example in which a variable-focus lens capable of changing the correction power of astigmatism is added to the correction optical system 120. For example, in Fig. 12, an astigmatism variable-focus lens 127 is disposed in place of the astigmatism lens 126 in the correction optical system 120 of Fig. 2. The variable-focus lens 127 uses an optical element that can electrically change the correction power and astigmatism axis angle of astigmatism, and a driving unit 127A allows the correction power to be continuously changed and the astigmatism axis angle to be changed in any direction. For example, the astigmatism variable-focus lens 127 uses a liquid lens that can change the focal length and astigmatism axis direction of astigmatism by applying a voltage.

[0063] For example, the test for astigmatism in which the variable-focus lens 127 and the variable prism 122 are synchronously controlled is applied to at least one of the astigmatism axis test step S5 and the astigmatism power test step S6. For example, in these astigmatism tests, a point cloud test target is presented by the test target presenting unit 200 as a test target.

[0064] For example, in the astigmatic axis testing step S5, the variable-focus lens 127 is controlled in a first astigmatic axis direction with a first astigmatic correction power as the first presentation state ST1. Furthermore, in a second presentation state ST2, the variable-focus lens 127 is controlled in a second astigmatic axis direction, which is changed from the first astigmatic axis direction, while maintaining the first astigmatic correction power. For example, the second astigmatic axis direction is changed by a predetermined amount from the first astigmatic axis direction. Synchronously with this control, the prism amount of the variable prism 122 is controlled based on the size of the target. By repeatedly switching between the first presentation state ST1 and the second presentation state ST2 at high speed, for example, as shown in FIG. 13 , the target CH of the point cloud in the first presentation state ST1 is presented to the test eye at a position Md1 on the left side, and the target CH of the point cloud in the second presentation state ST2 is presented to the test eye at a position Md2 on the right side, so that the target CH is simultaneously viewed. This allows the subject to simultaneously compare the optotype CH in two presentation states with different astigmatic axis directions without relying on memory, allowing for more efficient testing.

[0065] Furthermore, in the astigmatism power test step S6, the astigmatism correction power is changed between the first presentation state ST1 and the second presentation state ST2 while the astigmatism axis angle of the variable-focus lens 127 remains the same. By repeatedly switching between the first presentation state ST1 and the second presentation state ST2 at high speed, the same point cloud of optotypes CH are presented at different positions substantially simultaneously, as in Figure 13. This allows the subject to simultaneously compare the optotypes CH in the two presentation states with different astigmatism correction powers without relying on memory, allowing for more efficient testing.

[0066] Furthermore, the variable prism 122 and the astigmatic variable-focus lens 127 may be used instead of a cross cylinder lens. This allows the subject to see targets presented substantially simultaneously to easily compare how the subject sees the objects before and after the inversion of the cross cylinder lens.

[0067] In the above, an example was described in which an astigmatic variable-focus lens 127 is provided in addition to the spherical variable-focus lens 124, but an optical element such as a liquid lens that can change the correction power for both spherical and astigmatic lenses with a single variable-focus lens may also be used.

[0068] <Simultaneous presentation of near and far targets> The above explanation has been given for the case of comparing optotypes for distance vision or for near vision, but the comparison mode of the present disclosure, which controls the variable prism 122 and the variable-focus lens 124 in a synchronized manner, may also be applied to a test in which an optotype for distance vision and an optotype for near vision are presented substantially simultaneously to check how they appear.

[0069] 14 is a diagram illustrating an example of simultaneous near and far target presentation. For example, one of the auxiliary lenses 128 of the lens disk 128B included in the correction optical system 120 is additionally provided with a variable lens 128e that optically changes the presentation distance of the target. For example, in the first presentation state ST1, the variable prism 122 is controlled to present the target CH in a target direction LSe1, and the variable lens 128e is controlled to present the target CH at a far distance (e.g., 5 m). On the other hand, in the second presentation state ST2, the variable prism 122 is controlled to present the target CH in a target direction LSe2 below the target direction LSe1, and the variable lens 128e is controlled to present the target CH at a near distance (e.g., 40 cm). For example, the variable focus lens 124 (not shown in FIG. 14) arranged in the correction optical system 120 is set to the distance correction power of the prescription tested for distance vision in the power adjustment test step S10 of FIG. 5.

[0070] The variable prism 122 and the variable lens 128e are controlled to repeatedly switch between the first presentation state ST1 and the second presentation state ST2 at high speed, so that the far vision target CH and the near vision target CH are presented to the subject's eye substantially simultaneously, allowing the subject's eye to easily compare how the far vision and near vision target CH appear.

[0071] <Example of transformation> Although typical embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and various modifications are possible.

[0072] For example, if a wide range of correction power change is required and one variable lens (variable-focus lens 124, 127) cannot cover the entire range of correction power change, multiple variable lenses may be provided. Alternatively, the variable lenses may be used in combination with a lens with a switchable correction power that can be positioned on the examination optical axis LS1.

[0073] Furthermore, although the above describes an inspection in the comparison mode in which the variable prism 122 is controlled, it is also possible to make it possible to select between the conventional normal mode (a mode in which the variable prism 122 is not controlled) and the comparison mode.

[0074] In the above description, the visual targets are presented in a row, but this is not limiting. For example, the variable prism 122 may be controlled so that the visual targets are presented in a horizontal row, aligned vertically. Alternatively, the variable prism 122 may be controlled so that the visual targets are presented in a vertical and horizontal array, such as at the top right, top left, bottom right, and bottom left.

[0075] In the above description, the optotype is presented by the display 212 of the optotype presenting unit 200 in the addition power test step of the near vision test, but this is not limited to this. For example, a near vision chart printed on paper may also be used. The near vision chart is provided on a near point rod, and a fixed optotype placed at a distance desired by the subject can be used. In the optometry device 1 of the present disclosure, control of the display 212 in synchronization with control of the variable lens (variable focus lens 124, etc.) is not required, and a fixed optotype can be presented to the subject's eye. Therefore, a conventional optotype presenting device can be used to present the optotype, without the need for a dedicated optotype presenting device. [Explanation of symbols]

[0076] 1. Optometry equipment 50 control section 100 measurement units 120 Corrective optical system 122 Variable Prism 124 Variable Focus Lens 150 control section 200 Visual target presentation unit 300 Controller 310 Monitor 330 Storage section LS1 inspection optical axis CH optotype

Claims

1. An optometry device that presents a visual target to an eye to be examined and subjectively examines optical characteristics of the eye, a corrective optical system having a variable lens whose correction power can be electrically changed and a variable prism whose prism amount can be electrically changed; a control means; The control means controls the change in the correction power of the variable lens and the change in the prism amount of the variable prism in synchronization with each other, thereby presenting the target presented through the correction optical system at different correction powers and different positions so that it can be seen by the subject's eye substantially simultaneously.

2. The optometric apparatus of claim 1, The control means is capable of switching between at least two presentation states: a first presentation state in which a visual target is presented at a first position using a first prism amount of the variable prism with a first corrective power of the variable lens; and a second presentation state in which a visual target is presented at a second position using a second prism amount of the variable prism with a second corrective power of the variable lens, and by repeating this switching, visual targets in at least two presentation states are presented to the subject's eye substantially simultaneously.

3. The optometric apparatus of claim 2, a notification means for notifying an examiner of optometry information; The optometry apparatus, wherein the notification means notifies information relating to the correction power of the variable lens in each presentation state and information relating to the presentation position of the optotype in each presentation state.

4. In the optometry device according to any one of claims 1 to 3, an information acquiring means for acquiring size information of the optotype presented to the subject's eye, The optometry apparatus is characterized in that the control means changes the prism amount of the variable prism based on the acquired size information of the optotype.

5. The optometric apparatus of claim 4, a transmitter that transmits a selection signal for the target to a target presenting unit that presents the target; the information acquisition means includes a storage means for storing size information of the target; The optometry device is characterized in that the control means changes the prism amount of the variable prism based on size information of the optotypes acquired for each optotype selected by the selection signal.

6. The optometric apparatus according to any one of claims 1 to 5, An optometric apparatus, wherein the variable lens includes at least one of a first variable-focus lens capable of changing a spherical correction power and a second variable-focus lens capable of changing a correction power for astigmatism.

7. An optometry device that presents a visual target to an eye to be examined and subjectively examines the optical characteristics of the eye, the optometry device having a correction optical system that includes a variable lens that can electrically change the correction power and a variable prism that can electrically change the prism amount, comprising: By being executed by the control unit of the optometry apparatus, a control step of synchronously controlling a change in the correction power of the variable lens and a change in the prism amount of the variable prism, so that the target presented via the correction optical system is presented at different correction powers and at different positions so as to be visible to the eye to be examined substantially simultaneously; A control program for an optometric apparatus, characterized in that the program is executed by the optometric apparatus.

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