Ophthalmic device and control method for ophthalmic device

Abstract

To provide an ophthalmic device that can improve the ease of simultaneously comparing the appearance of two sets of lines extending in mutually orthogonal directions. [Solution] An ophthalmic device 1 comprises a display unit 22 capable of displaying an astigmatism test chart 45 for obtaining the astigmatism axis angle, and a control unit that controls the display unit 22 to rotate and display the astigmatism test chart 45 within the display unit 22. The astigmatism test chart 45 has a first target 46 consisting of a plurality of first straight lines 46a arranged in parallel at predetermined intervals, and a second target 47 consisting of a plurality of second straight lines 47a arranged in parallel at predetermined intervals and extending in a direction perpendicular to the first straight lines 46a. The first target 46 is displayed in a circular first region 48. The second target 47 is displayed in a ring-shaped second region 49 surrounding the first region 48.

Description

Technical Field

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[0001] The present disclosure relates to an ophthalmic device and a method for controlling an ophthalmic device.

Background Art

[0002] There is known an ophthalmic device capable of rotating and displaying a refractive error test chart composed of two types of straight line groups that form a 90° angle with each other in order to voluntarily obtain the axial angle of the refractive error axis of a subject (see, for example, Patent Document 1 and Patent Document 2). The axial angle of the refractive error axis is obtained based on how the subject simultaneously compares the appearance of the two types of straight line groups.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The ophthalmic device described in Patent Document 1 displays a refractive error test chart in which two types of straight line groups are separately arranged and the ends of each straight line group are delimited by a contour line. Therefore, the subject has to move their line of sight to view the two types of straight line groups, and there is a drawback that it is difficult to simultaneously compare the appearance of the straight line groups.

[0005] On the other hand, the ophthalmic device described in Patent Document 2 displays a refractive error test chart in which the opposing ends of two types of straight line groups are arranged on a virtual straight line where they are adjacent or coincide. Therefore, the ophthalmic device described in Patent Document ② can suppress the movement of the subject's line of sight when simultaneously comparing the two types of straight line groups. However, since the two types of straight line groups are arranged facing each other with a virtual straight line in between, there is room for improvement in the ease of simultaneously comparing the appearance of the two types of straight line groups.

[0006] This disclosure addresses the above-mentioned problem and aims to provide an ophthalmic device and a control method for the ophthalmic device that can improve the ease of simultaneously comparing the appearance of two sets of lines extending in mutually orthogonal directions. [Means for solving the problem]

[0007] To achieve the above objective, the ophthalmic apparatus of this disclosure comprises a display unit capable of displaying an astigmatism test chart for obtaining the astigmatism axis angle of a subject, and a control unit that controls the display unit to rotate and display the astigmatism test chart within the display unit, wherein the astigmatism test chart has a first target consisting of a plurality of first straight lines arranged in parallel at predetermined intervals, and a second target consisting of a plurality of second straight lines arranged in parallel at predetermined intervals and extending in a direction perpendicular to the first straight lines, wherein the first target is displayed in a circular first region, and the second target is displayed in a ring-shaped second region surrounding the first region.

[0008] To achieve the above objective, the control method for an ophthalmic device of the present disclosure includes a display unit capable of displaying an astigmatism test chart for obtaining the astigmatism axis angle of a subject, and a control unit that controls the display unit to rotate and display the astigmatism test chart within the display unit, the control method including an astigmatism test chart display step of displaying the astigmatism test chart on the display unit, the astigmatism test chart having a first target consisting of a plurality of first lines arranged in parallel at predetermined intervals, and a second target consisting of a plurality of second lines arranged in parallel at predetermined intervals and extending in a direction perpendicular to the first lines, wherein the astigmatism test chart display step is configured to display the first target in a circular first region and the second target in a ring-shaped second region surrounding the first region. [Effects of the Invention]

[0009] The ophthalmic apparatus and control method for the ophthalmic apparatus described herein, configured in this manner, make it easier to simultaneously compare the appearance of two sets of lines extending in mutually orthogonal directions. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram showing an ophthalmic device according to the first embodiment. [Figure 2] This is an explanatory diagram showing the control system in the ophthalmic device of the first embodiment. [Figure 3] This is a schematic external view of the second controller. [Figure 4] This is an explanatory diagram showing a radial chart. [Figure 5] This is an explanatory diagram showing an astigmatism test chart. [Figure 6A] This is an explanatory diagram showing the brightness of the first target. [Figure 6B] This is an enlarged view showing a portion of the first straight line. [Figure 7] This is an explanatory diagram showing the brightness of the second target. [Figure 8] This flowchart shows an example of an astigmatism examination procedure using the ophthalmic device of the first embodiment. [Figure 9] This is a perspective view showing an ophthalmic device according to a second embodiment. [Figure 10] This is an explanatory diagram showing an astigmatism test chart for modified cases. [Modes for carrying out the invention]

[0011] Embodiments for implementing the ophthalmic apparatus and control method of the ophthalmic apparatus described herein will be described below with reference to the drawings. In this specification, the X, Y, and Z axes are defined as shown in Figures 1 and 9. The X direction is the left-right direction as viewed from the subject S (eye under examination). The Y direction is the up-down direction as viewed from the subject S (eye under examination), i.e., the vertical direction. The Z direction is the direction perpendicular to the X and Y directions, i.e., the front-back direction as viewed from the subject S (eye under examination).

[0012] (First Embodiment) The ophthalmic device 1 of the first embodiment is an ophthalmic device capable of performing at least a refractive error examination. The refractive error examination is an examination for voluntarily obtaining the axial angle (refractive error axis angle) and refractive error degree of the refractive error axis of the subject S. That is, the examiner E presents a refractive error examination chart 45 (see FIG. 5), which is a visual target O for refractive error examination, to the subject S using the ophthalmic device 1. Then, the refractive error axis angle and refractive error degree are obtained based on the response of the subject S to the refractive error examination chart 45.

[0013] In addition, the ophthalmic device 1 may be capable of performing subjective examinations such as, for example, a distant visual acuity examination, a near visual acuity examination, a contrast sensitivity examination, a glare examination, and a visual field examination, in addition to the refractive error examination. A subjective examination is an examination for obtaining eye characteristics based on the response of the subject S who has visually observed the visual target O. The distant visual acuity examination is an examination for measuring the visual acuity for seeing far away. The near visual acuity examination is an examination for measuring the visual acuity for seeing nearby. The contrast sensitivity examination is an examination for measuring the ability of the subject S to distinguish subtle differences in brightness. The glare examination is an examination for obtaining the influence of a decrease in the contrast of the retinal image of the subject S, so-called glare impairment. The visual field examination is an examination for measuring the range and defects of the visual field of the subject S.

[0014] As shown in FIG. 1, the ophthalmic device 1 includes a subjective refractometer 10, a visual target presentation device 20, and an operation device 30 (see FIG. 2).

[0015] The subjective refractometer 10 is a device that is installed in front of the subject S and selectively arranges an arbitrary optical element including cylindrical lenses with different powers in the optical path in the line-of-sight direction of the examined eye. That is, the optical element is arranged between the examined eye and the refractive error examination chart 45 described later by the subjective refractometer 10. The subjective refractometer 10 is held via a support arm 4 on a support column 3 attached to the top plate of the examination table 2.

[0016] The support column 3 has a cylindrical shaft 3a and a movable shaft 3b whose lower end is held by the cylindrical shaft 3a. The movable shaft 3b is movable in the Y direction by manual operation or a drive mechanism (not shown). As the drive mechanism, a feed screw mechanism or a cylinder device that can be rotationally driven by a drive motor is used. Further, one end of the support arm 4 is attached to the movable shaft 3b, and the other end extends obliquely upward. The support arm 4 is rotatable about the movable shaft 3b. The autorefractor 10 is suspended from the tip of the support arm 4.

[0017] As shown in FIG. 1, the autorefractor 10 has a pair of eye examination units 10L and 10R respectively corresponding to the left and right eyes to be examined. Each of the eye examination units 10L and 10R has a housing 11L and 11R respectively. Inside the housings 11L and 11R, a plurality of turret plates (not shown), a first drive mechanism 12 (see FIG. 2), and a second drive mechanism 13 (see FIG. 3) are provided respectively.

[0018] The housings 11L and 11R are formed with eye examination windows LW and RW. The eye examination windows LW and RW are openings penetrating the housings 11L and 11R. The subject S can visually recognize the front through the autorefractor 10 by looking through the eye examination windows LW and RW.

[0019] The plurality of turret plates are circular plates of the same shape and are arranged side by side in the thickness direction. Further, each turret plate is rotatably held inside the housings 11L and 11R. Furthermore, a plurality of optical elements are provided on the same circumference of each turret plate. The optical elements include a plurality of spherical lenses, rotary prisms, cross cylinders, wavefront modulation elements, polarizing plates, etc. with different diopters in addition to a plurality of cylindrical lenses with different diopters. Note that specific optical elements such as cylindrical lenses and cross cylinders are rotatably attached to the turret plates. The axial direction of the cylindrical lens is changed by rotating it with respect to the turret plate. Then, when each turret plate rotates, one of the optical elements faces the eye examination windows LW and RW.

[0020] The first drive mechanism 12 and the second drive mechanism 13 are, for example, pulse motors. The first drive mechanism 12 is driven based on a control signal from the operating device 30 and rotates each of the multiple turret plates independently. This allows the subjective optometry device 10 to selectively position one of the multiple optical elements in the optical path in the line of sight direction of the eye being examined. The second drive mechanism 13 is also driven based on a control signal from the operating device 30 and rotates each of the optical elements that are rotatably mounted on the turret plates independently. This allows the subjective optometry device 10 to set the axial direction of, for example, a cylindrical lens in any direction. In other words, in the ophthalmic device 1 of the first embodiment, the subjective optometry device 10 constitutes a measuring optical system including optical elements (multiple cylindrical lenses) whose power and axial direction can be changed.

[0021] The target presentation device 20 is a device that presents any target O, including an astigmatism test chart 45, in front of the eye being examined. The target presentation device 20 has a display housing 21 and a display unit 22.

[0022] The display unit 22 is located inside the display housing 21 and is visible through an opening 21a formed on the front of the display housing 21. The display unit 22 is controlled by a control signal from the operating device 30 and displays an arbitrary target O in the target presentation area 22a. The display unit 22 is composed of a liquid crystal display (LCD), an organic electroluminescent (EL) display, a plasma display, or the like.

[0023] The target presentation area 22a is rectangular in shape. The targets O displayed in the target presentation area 22a are switched or their display state is changed based on control signals from the operating device 30. In addition to the astigmatism test chart 45, the targets O displayed in the target presentation area 22a may include, for example, the radial chart 41 (described later), Landolt rings, letters (i.e., alphabet, hiragana, katakana), numbers, E-shaped targets, etc.

[0024] The operating device 30 includes a first controller 31 and a second controller 35.

[0025] The first controller 31 is an information processing device that transmits control signals to the ophthalmography units 10L and 10R and the target presentation device 20. The first controller 31 is composed of, for example, a notebook computer or a desktop computer. The first controller 31 may be a controller dedicated to the ophthalmological device 1. Alternatively, the first controller 31 may be a portable device carried by the examiner E, such as a tablet terminal or a smartphone. As shown in Figure 2, the first controller 31 has an examiner operation unit 32, an examiner display unit 33, and a control unit 34.

[0026] The examiner's control unit 32 includes a group of switches for multiple eye examination operations, a dial used for strabismus testing, a group of switches used for visual acuity testing, and the like. The examiner's control unit 32 is operated by examiner E. The examiner's control unit 32 receives operations from examiner E and transmits operation signals corresponding to the received operations. The operation signals are transmitted to the control unit 34.

[0027] The examiner display unit 33 consists of a touch panel display provided on the first controller 31 and has a transmit button. Examiner E may perform a predetermined transmission by operating the transmit button set on the examiner display unit 33. The examiner display unit 33 is controlled by a control signal from the operating device 30 and displays inspection information, etc. The examiner display unit 33 also receives operations from examiner E and transmits an operation signal corresponding to the received operation. The operation signal is transmitted to the control unit 34.

[0028] The control unit 34 is an information processing mechanism that performs various calculation and control processes. The control unit 34 includes a Central Processing Unit (CPU), Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), programmable logic device circuits such as Simple Programmable Logic Device (SPLD), Complex Programmable Logic Device (CPLD), and Field Programmable Gate Array (FPGA), memory circuits, and memory devices. The control unit 34 transmits predetermined control signals based on operation signals transmitted from the examiner's operation unit 32 or the examiner's display unit 33. The control unit 34 also transmits predetermined control signals based on operation signals transmitted from the second control unit 37, which will be described later. The control signals transmitted from the control unit 34 are transmitted to the first drive mechanism 12 and the second drive mechanism 13 of the ophthalmography units 10L and 10R, the display unit 22 of the visual target presentation device 20, and the examiner's display unit 33. As a result, the ophthalmography units 10L and 10R, the display unit 22 of the visual target presentation device 20, and the examiner's display unit 33 are all centrally controlled by the control unit 34.

[0029] The second controller 35 is a subject controller that receives operations from the subject S and transmits predetermined operation signals to the control unit 34 of the first controller 31. The second controller 35 includes a subject operation unit 36 ​​and a second control unit 37.

[0030] As shown in Figure 3, the subject's control unit 36 ​​includes a dial member 36a and a push button 36b. The dial member 36a has a cylindrical shape. The dial member 36a rotates around a rotation axis (not shown) located in the center. The push button 36b is located below the dial member 36a. The push button 36b is pressed.

[0031] The second control unit 37 transmits operation signals in response to the subject S's actions on the subject operation unit 36. Specifically, the second control unit 37 transmits operation signals based on the rotation angle, rotation direction, and rotation speed of the dial member 36a, and whether or not the push button 36b is pressed. The operation signals are transmitted to the control unit 34.

[0032] The control unit 34 then transmits a control signal to the display unit 22, controlling the display unit 22 of the target presentation device 20 to display the radial chart 41 or the astigmatism test chart 45 on the display unit 22. Furthermore, the control unit 34 controls the display unit 22 to rotate the astigmatism test chart 45 within the target presentation area 22a of the display unit 22. "Rotation display" means that after displaying the astigmatism test chart 45 in a predetermined state within the target presentation area 22a, the astigmatism test chart 45 displayed in the target presentation area 22a is rotated within the target presentation area 22a around an arbitrarily set rotation center point. The rotation angle and rotation speed of the astigmatism test chart 45 can be set arbitrarily.

[0033] The radial chart 41 is a target O used to obtain the approximate astigmatism axis angle of the subject S. As shown in Figure 4, the radial chart 41 is a target O having multiple radial lines 42. The multiple radial lines 42 are multiple straight lines extending radially from a virtual center point X set in the center of the target presentation area 22a. Each radial line 42 extends in a direction that divides the entire radial direction, i.e., 360°, into multiple (in this case 24) sections at predetermined angles (in this case 15°). Note that the virtual center point X is not displayed.

[0034] Furthermore, the control unit 34 transmits a control signal to the display unit 22, causing the target presentation device 20 to display the radial chart 41 and, at the same time, to display a marker 43 near the tip of any of the radial lines 42. Note that "near the tip of the radial line 42" means a predetermined position around the tip of the radial line 42. The marker 43 may be placed in a position continuous with the radial line 42, or in a position where there is a gap between it and the end of the radial line 42. The marker 43 is, for example, a circle with a diameter slightly larger than the width of the radial line 42.

[0035] The control unit 34 then transmits a control signal to the display unit 22, causing the marker display 43 to move sequentially along the circumferential direction of the radial chart 41. Furthermore, the control unit 34 transmits a control signal to the display unit 22, causing the marker display 43 to be fixed near the tip of the radial line 42 that the subject S clearly sees, in response to the subject S's operation received by the subject operation unit 36.

[0036] The astigmatism test chart 45 is a target O for obtaining the astigmatism axis angle and degree of astigmatism of the subject S. As shown in Figure 5, the astigmatism test chart 45 has a first target 46 and a second target 47.

[0037] The first target 46 is composed of multiple first straight lines 46a arranged parallel to each other at predetermined intervals. The first target 46 is displayed in the first region 48 set in the target presentation area 22a. The first region 48 is a circular area centered on a virtual center point X set in the center of the target presentation area 22a. In Figure 5, the first region 48 is enclosed by a dashed line. Note that the dashed line and the virtual center point X surrounding the first region 48 are not actually displayed. The size of the first region 48 can be set arbitrarily.

[0038] Furthermore, as shown in Figure 6A, the brightness in the width direction of each of the multiple first lines 46a changes according to a sine function. In other words, the first target 46 is a striped pattern of spatial frequencies. As a result, each first line 46a is a straight line with indistinct side edges, which are the width direction contours, as shown in Figure 6B. In addition, the width W1 of each first line 46a is set to be the same length as each other. Moreover, the spacing W2 between the first lines 46a is set to be the same length as the width W1 of the first lines 46a.

[0039] The second target 47 is arranged in parallel at predetermined intervals and consists of multiple second lines 47a extending perpendicular to the first line 46a. The second target 47 is displayed in the second region 49 set in the target presentation area 22a. The second region 49 is an annular region that surrounds the first region 48 with a constant width all around. In Figure 5, the second region 49 is enclosed by a dashed line. Note that the dashed line surrounding the second region 49 is not actually displayed. The width of the second region 49 can be set arbitrarily, and the area ratio of the first region 48 to the second region 49 can also be set arbitrarily.

[0040] Furthermore, the boundary between the first region 48 and the second region 49 almost coincides here. In other words, there is almost no gap between the first region 48 and the second region 49. Therefore, the ends of some of the multiple first lines 46a that constitute the first target 46 are almost continuous with one of the multiple second lines 47a that constitute the second target 47.

[0041] Furthermore, as shown in Figure 7, the brightness in the width direction of each of the multiple second lines 47a changes according to a sine function. In other words, the second target 47 is a striped pattern of spatial frequencies. As a result, each second line 47a, like the first line 46a, is a straight line with indistinct side edges that form the width direction contour (see Figure 6B). In addition, the width W3 of each second line 47a is set to be the same length as the width W1 of the first line 46a. Moreover, the spacing W4 between the second lines 47a is set to be the same length as the width W3 of the second line 47a.

[0042] In other words, in the astigmatism test chart 45, the width W1 of the multiple first lines 46a, the interval W2 between the first lines 46a, the width W3 of the multiple second lines 47a, and the interval W4 between the second lines 47a are all set to the same length.

[0043] Furthermore, at least one of the following can be adjusted, or changed, by the subject S while looking at the astigmatism test chart 45: the width W1 of the multiple first straight lines 46a, the interval W2 between the first straight lines 46a, the width W3 of the multiple second straight lines 47a, and the interval W4 between the second straight lines 47a.

[0044] In this case, for example, the display unit 22 stores in advance multiple first targets 46 with different spatial frequencies of striped patterns, and multiple second targets 47 with different spatial frequencies of striped patterns. The second control unit 37 then transmits a predetermined operation signal to the control unit 34 based on the operation of the subject operation unit 36 ​​by the subject S. The control unit 34 transmits a control signal to the display unit 22 based on the operation signal transmitted from the second control unit 37. The control unit 34 then selects either the first target 46 or the second target 47, which consists of striped patterns with spatial frequencies corresponding to the operation of the subject S, and displays it on the display unit 22. As a result, at least one of the width W1 of each first line 46a, the spacing W2 between the first lines 46a, the width W3 of each second line 47a, and the spacing W4 between the second lines 47a is changed based on the operation of the subject S received by the subject operation unit 36.

[0045] Furthermore, the control unit 34 transmits a control signal to the display unit 22 to stop the rotation of the astigmatism test chart 45 when the subject S can clearly see the first target 46. The control unit 34 then sets a predetermined angle based on the inclination direction of the first target 46 when the rotation has stopped. The control unit 34 then transmits a control signal to the second drive mechanism 13 to rotate the cylindrical lens relative to the turret plate and align the axial direction of all the cylindrical lenses in the subjective eye examination device 10 with the set predetermined angle. Furthermore, the control unit 34 transmits a control signal to the first drive mechanism 12 to rotate the turret plate to which the multiple cylindrical lenses are attached and change the power of the cylindrical lenses so that the subject S can clearly see the second target 47. In other words, the control unit 34 positions a cylindrical lens that allows the subject S to clearly see the second target 47 between the subject's eye and the astigmatism test chart 45.

[0046] Figure 8 shows an example of the examination flow for astigmatism testing performed using the ophthalmic device 1 of the first embodiment. The astigmatism test is initiated by the examiner E operating the first controller 31.

[0047] In step S1, the control unit 34 transmits a control signal to the target presentation device 20 based on the operation signal transmitted from the first controller 31. The control unit 34 then displays the radial chart 41 on the display unit 22. Here, the radial chart 41 is displayed in the center of the target presentation area 22a. After this, the flow proceeds to step S2. The radial chart 41 is viewed by the subject S.

[0048] In step S2, the control unit 34 transmits a control signal to the target presentation device 20. The control unit 34 then causes the display unit 22 to display a marker 43. Here, the marker 43 is displayed near the tip of one of the pre-set radial lines 42. After this, the flow proceeds to step S3. The marker 43 is visually confirmed by the subject S.

[0049] In step S3, the control unit 34 transmits a control signal to the target presentation device 20. The control unit 34 then sequentially moves the position where the marker display 43 is displayed along the circumferential direction of the radial chart 41. The timing of moving the marker display 43 may be predetermined or determined based on the examiner E's operation of the examiner's control unit 32. Furthermore, the control unit 34 may also move the marker display 43 based on the subject S's operation of the subject's control unit 36. The direction of movement of the marker display 43 may also be predetermined or determined based on the examiner E's operation of the examiner's control unit 32 or the subject S's operation of the subject's control unit 36. After this, the flow proceeds to step S4.

[0050] At this point, examiner E asks subject S which radial line 42 appears the clearest. If examiner E receives a response from subject S that all radial lines 42 appear uniform, examiner E concludes that subject S does not have astigmatism and stops the astigmatism test.

[0051] In step S4, the examiner's control unit 32 receives an operation from examiner E to "stop the movement of the marker display 43 near the tip of the radial line 42 that subject S has seen most clearly." The operation of the examiner's control unit 32 by examiner E is based on the subject S's response after viewing the radial chart 41 and the marker display 43. The examiner's control unit 32 transmits an operation signal corresponding to the received operation to the control unit 34. The control unit 34 transmits a control signal to the target presentation device 20 in response to the transmitted operation signal, stopping the movement of the marker display 43. After this, the flow proceeds to step S5.

[0052] In step S5, the control unit 34 sets the inclination direction of the radial line 42 near the marker display 43 where movement has stopped as the first angle. Note that the "radial line 42 near the marker display 43 where movement has stopped" is the radial line 42 that subject S saw most clearly. After this, the flow proceeds to step S6.

[0053] In step S6, the examiner's control unit 32 receives an operation from examiner E to switch the target O displayed on the display unit 22 from the radial chart 41 to the astigmatism test chart 45. The examiner's control unit 32 transmits an operation signal corresponding to the received operation to the control unit 34. The control unit 34 transmits a control signal to the target presentation device 20 in response to the transmitted operation signal, causing the astigmatism test chart 45 to be displayed on the display unit 22. In other words, step S6 corresponds to the astigmatism test chart display step in which the astigmatism test chart 45 is displayed on the display unit 22.

[0054] Here, the astigmatism test chart 45 is displayed in the center of the target presentation area 22a. The control unit 34 also displays the astigmatism test chart 45 with the first straight line 46a aligned with the first angle set in step S5. As a result, the rotation of the astigmatism test chart 45 begins from the position where the first straight line 41a is aligned with the first angle. The astigmatism test chart 45 is also viewed by the subject S. After this, the flow proceeds to step S7.

[0055] In step S7, the dial member 36a accepts operation from the subject S who has viewed the astigmatism test chart 45. That is, the subject S views the astigmatism test chart 45 and simultaneously compares how the first target 46 and the second target 47 (hereinafter referred to as "two types of straight line groups") appear. Then, based on how the astigmatism test chart 45 appears to the subject S rotates the dial member 36a of the subject operation unit 36. At this time, the subject S adjusts the rotation angle and direction of the dial member 36a so that the first target 46 appears the clearest and the second target 47 appears the least clear.

[0056] The second control unit 37 transmits an operation signal corresponding to the rotation angle and direction of the dial member 36a, which is the operation received by the dial member 36a, to the control unit 34. The control unit 34 transmits a control signal to the target presentation device 20 in response to the transmitted operation signal, and rotates the astigmatism test chart 45 around the virtual center point X. In other words, the astigmatism test chart 45 rotates based on the operation of the subject S to the second controller 35. After this, the flow moves to step S8. Step S7 corresponds to the rotation display step in which the astigmatism test chart 45 is rotated and displayed in the display unit 22.

[0057] Furthermore, at this time, the control unit 34 may change the width W1 of each first straight line 46a or the spacing W2 between the first straight lines 46a based on the operation of the subject operation unit 36 ​​by the subject S. In addition, the control unit 34 may change the width W3 of each second straight line 47a or the spacing W24 between the second straight lines 47a based on the operation of the subject operation unit 36 ​​by the subject S. In other words, step S7 corresponds to a spacing change step in which the second controller 35 changes at least one of the width W1 of the multiple first straight lines 46a, the spacing W2 between the first straight lines 46a, the width W3 of the multiple second straight lines 47a, and the spacing W4 between the second straight lines 47a based on the operation of the subject S received by the second controller 35.

[0058] In step S8, the push button 36b accepts operation from the subject S. That is, the subject S presses the push button 36b at the timing when the first target 46 is most clearly visible, based on how the astigmatism test chart 45 appears to them. The second control unit 37 receives an operation signal from the control unit 34 when the push button 36b is pressed. The control unit 34 receives the operation signal and sends a control signal to the target presentation device 20 to stop the rotation of the astigmatism test chart 45. In other words, step S8 corresponds to a stopping step in which the rotation of the astigmatism test chart 45 is stopped while the subject S is clearly viewing the first target 46.

[0059] As a result, the astigmatism test chart 45 is displayed in the state where subject S can see the first target 46 most clearly. When subject S sees the first target 46 most clearly, the second target 47 appears the least clear. In other words, subject S presses the push button 36b when they feel the difference in appearance between the first target 46 and the second target 47 is greatest. After this, the flow proceeds to step S9.

[0060] In step S9, the control unit 34 detects the angle of inclination of the first straight line 46a of the astigmatism test chart 45 whose rotation has stopped, and sets the detected angle as the second angle (predetermined angle). The "first straight line 46a of the astigmatism test chart 45 whose rotation has stopped" is the first target 46 in the state that the subject S can see most clearly. The "angle of inclination of the first straight line 46a" is the angle of inclination of the first straight line 46a with respect to the horizontal or vertical direction set within the target presentation area 22a.

[0061] The control unit 34 then transmits a control signal to the second drive mechanism 13, causing each cylindrical lens to rotate relative to the turret plate, and aligning the axial directions of the multiple cylindrical lenses to the second angle. Furthermore, the control unit 34 obtains the axial angle of the astigmatism axis of the eye under examination based on the second angle. After this, the flow proceeds to step S10. Step S9 corresponds to an axial adjustment step in which the axial direction of the cylindrical lenses (optical elements) is aligned to the second angle (predetermined angle) set based on the tilt direction of the first target 46 when its rotation has stopped.

[0062] In step S10, the dial member 36a accepts input from the subject S, who has once again viewed the astigmatism test chart 45. That is, the subject S views the astigmatism test chart 45, which has stopped rotating, and simultaneously compares how the two groups of lines appear. Then, based on how the astigmatism test chart 45 appears to the subject S, the subject S rotates the dial member 36a of the subject operation unit 36. At this time, the subject S adjusts the rotation angle and direction of the dial member 36a so that the first target 46 and the second target 47 appear to be of similar quality. Note that "the first target 46 and the second target 47 appear to be of similar quality" means that the subject S can clearly see both the first target 46 and the second target 47.

[0063] The second control unit 37 transmits an operation signal to the control unit 34 according to the rotation angle and direction of the dial member 36a. The control unit 34 transmits a control signal to the first drive mechanism 12 in response to the transmitted operation signal. The control unit 34 then rotates the turret plate to position one of the multiple cylindrical lenses facing the eye examination windows LW and RW. This adjusts the power of the cylindrical lens positioned in the optical path in the line of sight of the eye being examined. After this, the flow proceeds to step S11.

[0064] In step S11, the push button 36b accepts operation from the subject S. That is, the subject S presses the push button 36b at a time when the first target 46 and the second target 47 appear to be roughly the same, based on how the astigmatism test chart 45 looks to them. The second control unit 37 receives an operation signal from the control unit 34 when the push button 36b is pressed. The control unit 34 then receives the operation signal and sends a control signal to the first drive mechanism 12, stopping the rotation of the turret plate. The control unit 34 then obtains the astigmatism of the subject's eye based on the power of the cylindrical lens facing the eye examination windows LW and RW. After this, the flow moves to the end. Steps S10 and S11 correspond to power adjustment steps in which the power of the cylindrical lens (optical element) is changed so that the subject S can clearly see the second target 47, with the axial direction of the cylindrical lens (optical element) aligned with the second angle (predetermined angle).

[0065] The effects and benefits of the ophthalmic device 1 of the first embodiment are described below.

[0066] The ophthalmic device 1 includes a display unit 22 capable of displaying an astigmatism test chart 45 for obtaining the astigmatism axis angle of the eye under examination, and a control unit 34 that controls the display unit 22. The control unit 34 rotates and displays the astigmatism test chart 45 within the target presentation area 22a of the display unit 22. Here, the astigmatism test chart 45 has a first target 46 and a second target 47. The first target 46 consists of a plurality of first straight lines 46a arranged in parallel at predetermined intervals. The second target 47 consists of a plurality of second straight lines 47a arranged in parallel at predetermined intervals and extending in a direction perpendicular to the first straight lines 46a. The first target 46 is displayed in a circular first area 48. The second target 47 is displayed in a ring-shaped second area 49 that surrounds the first area 48.

[0067] In other words, the control method for the ophthalmic device 1 includes an astigmatism test chart display step (step S6) which displays an astigmatism test chart 45 on the display unit 22, the chart having a first target 46 consisting of a plurality of first straight lines 46a arranged in parallel at predetermined intervals, and a second target 47 consisting of a plurality of second straight lines 47a arranged in parallel at predetermined intervals and extending in a direction perpendicular to the first straight lines 46a.

[0068] Therefore, the ophthalmic device 1 can simultaneously compare the appearance of two sets of lines extending in mutually orthogonal directions by comparing the central and peripheral portions of the astigmatism test chart 45. This makes it easier for the subject S to recognize the difference in appearance between the first target 46 and the second target 47 when viewing the astigmatism test chart 45. Thus, the ophthalmic device 1 can improve the ease of simultaneously comparing the appearance of two sets of lines extending in mutually orthogonal directions.

[0069] Furthermore, the degree of difference in how the two types of straight line groups appear differs for each subject S, depending on the striped pattern of the first target 46 or the second target 47. In other words, there is a striped pattern for each subject S that makes the difference in appearance easily noticeable.

[0070] In contrast, the ophthalmic device 1 includes a second controller 35 that receives operations from the subject S and transmits a predetermined operation signal to the control unit 34. The control unit 34 then changes at least one of the following based on the operations from the subject S received by the second controller 35: the width W1 of the multiple first straight lines 46a, the spacing W2 between the first straight lines 46a, the width W3 of the multiple second straight lines 47a, and the spacing W4 between the second straight lines 47a.

[0071] In other words, the control method for the ophthalmic device 1 includes a spacing change step (step S7) in which the second controller 35 changes at least one of the following based on the operation of the subject S received by the second controller 35: the width W1 of a plurality of first straight lines 46a, the spacing W2 between the first straight lines 46a, the width W3 of a plurality of second straight lines 47a, and the spacing W4 between the second straight lines 47a.

[0072] This allows the ophthalmic device 1 to change the width W1 of multiple first straight lines 46a based on the subject S's own instructions according to how the subject S sees them. In other words, the subject S can change the striped pattern of the first target 46 or the second target 47 to a state that makes it easier to recognize the difference in appearance, according to their own instructions. As a result, the ophthalmic device 1 can further improve the ease of simultaneously comparing the appearance of two different groups of straight lines.

[0073] Furthermore, if the outlines of multiple first lines 46a and multiple second lines 47a are clear, the first lines 46a and second lines 47a will be shown in a single color. Therefore, subject S has difficulty recognizing the subtle difference between when the first target 46 and the second target 47 are clearly visible and when they are not.

[0074] In contrast, the astigmatism test chart 45 has unclear outlines for the first line 46a and the second line 47a. This allows the ophthalmic device 1 to partially change the color tone of the first line 46a and the second line 47a. Therefore, when a subject S with astigmatism views the astigmatism test chart 45, it becomes easier to recognize the subtle difference between when the first target 46 and the second target 47 are clearly visible and when they are not. Thus, the ophthalmic device 1 can easily make fine adjustments when rotating the astigmatism test chart 45.

[0075] In particular, in the first embodiment, the brightness of the first line 46a and the second line 47a in the width direction of the astigmatism test chart 45 changes according to a sine function. As a result, the first target 46 and the second target 47 become a striped pattern in which the brightness changes repeatedly at regular intervals, a so-called spatial frequency striped pattern. Therefore, the ophthalmic device 1 makes it easier for the subject S to recognize the subtle difference between when the first target 46 and the second target 47 are clearly visible and when they are not clearly visible.

[0076] Furthermore, the ophthalmic device 1 includes a subjective optometry device 10, which is positioned between the eye under examination and the astigmatism test chart 45 and includes multiple cylindrical lenses, which are optical elements whose power and axial direction can be changed.The control unit 34 controls the display unit 22 to rotate and display the astigmatism test chart 45 within the target presentation area 22a of the display unit 22.Based on the operation of the subject S, the control unit 34 stops the rotation of the astigmatism test chart 45 when the subject S can clearly see the first target 46.Next, the control unit 34 controls the second drive mechanism 13 of the subjective optometry device 10 to align the axial direction of the cylindrical lens with a second angle set based on the tilt direction of the first target 46 when the rotation of the astigmatism test chart 45 stopped.Furthermore, the control unit 34 controls the first drive mechanism 12 of the subjective optometry device 10 to change the power of the cylindrical lens so that the subject S can clearly see the second target 47.

[0077] In other words, the control method for the ophthalmic device 1 includes a rotation display step (step S7), a stop step (step S8), an axial adjustment step (step S9), and a power adjustment step (steps S10 and S11). In the rotation display step, the astigmatism test chart 45 is rotated and displayed within the display unit 22. In the stop step, the rotation of the astigmatism test chart 45 is stopped when the subject S can clearly see the first target 46. In the axial adjustment step, the axial direction of the cylindrical lens is aligned with a second angle set based on the tilt direction of the first target 46 when the rotation has stopped. In the power adjustment step, with the axial direction of the cylindrical lens aligned with the second angle, the power of the cylindrical lens is changed so that the subject S can clearly see the second target 47.

[0078] This allows the ophthalmic device 1 to accurately acquire the axis angle and degree of astigmatism of the subject S.

[0079] Furthermore, the control unit 34 displays a radial chart 41 consisting of multiple radial lines 42 extending in the radial direction using the display unit 22. The control unit 34 then displays the astigmatism test chart 45 with the first straight line 46a aligned with the radial line 42 (first angle) that the subject S clearly saw. In other words, the control unit 34 starts rotating the astigmatism test chart 45 from the position where the first straight line 46a is aligned with the radial line 42 that the subject S clearly saw.

[0080] Therefore, when the ophthalmic device 1 displays the astigmatism test chart 45, it can align the orientation of the first straight line 46a with an approximate orientation that can be clearly seen by the subject S. This makes it possible for the ophthalmic device 1 to determine the axis angle without significantly rotating the astigmatism test chart 45.

[0081] Furthermore, the control unit 34 displays the radial chart 41 on the display unit 22 and simultaneously displays a marker 43 near the tip of one of the multiple radial lines 42. The control unit 34 then sequentially moves the position where the marker 43 is displayed. In addition, based on the actions of the subject S, the control unit 34 fixes the position where the marker 43 is displayed near the tip of the radial line 42 that the subject S clearly sees.

[0082] This allows the ophthalmic device 1 to easily identify the radial lines 42 that the subject S clearly sees, to the examiner E and the control unit 34.

[0083] The ophthalmic device 1 includes a second controller 35 having a dial member 36a that is rotated by the subject S. The control unit 34 controls the display unit 22 and the subjective eye examination device 10 based on the rotation angle of the dial member 36a.

[0084] This allows the ophthalmic device 1 to adjust the rotation state of the astigmatism test chart 45 and the switching of cylindrical lenses in response to the operation of the dial member 36a by the subject S. In other words, the subject S can intuitively control the rotation state of the astigmatism test chart 45 and the switching of cylindrical lenses. As a result, the ophthalmic device 1 can acquire the axis angle and degree of astigmatism of the subject S with even greater accuracy.

[0085] (Second embodiment) The ophthalmic device 1A of the second embodiment shown in Figure 9 is an ophthalmic device capable of performing subjective examinations, including astigmatism testing, and objective examinations. Objective examinations involve irradiating the eye under examination with light and acquiring ocular characteristics of the eye based on the detection of the reflected light. Objective examinations include measurements to acquire the characteristics of the eye under examination and imaging to acquire images of the eye under examination. Furthermore, objective examinations include objective refraction measurement (refractive measurement), corneal topography measurement (keratometry), intraocular pressure measurement, fundus photography, and measurements using OCT.

[0086] Ophthalmic device 1A is a binocular open-type ophthalmic device that allows simultaneous measurement of ocular characteristics in both eyes while the subject S has both eyes open. It is also possible to measure ocular characteristics in each eye individually by occluding one eye or turning off the fixation target with ophthalmic device 1A.

[0087] As shown in Figure 9, the ophthalmic device 1A comprises a support base 50, a measurement unit 60, an examiner controller 70, a control unit 80, and a patient controller (not shown).

[0088] The support base 50 includes an eye examination table 51 that is installed on the floor and a support column 52 that rises from the eye examination table 51. The eye examination table 51 may be adjustable in the Y direction (height).

[0089] The measuring unit 60 includes an arm 61, a measuring head 62, and a forehead rest 63. One end of the arm 61 is supported by a support column 52, and the other end extends from the support column 52 toward the front (towards the subject) along the Z direction, with the measuring head 62 attached to its tip. As a result, the measuring head 62 is suspended from the support column 52 via the arm 61 above the eye examination table 51. The arm 61 is also movable in the Y direction relative to the support column 52. The arm 61 may also be movable in the X and Z directions relative to the support column 52.

[0090] The measuring head 62 is the part that measures the ocular characteristics of the eye being examined. The measuring head 62 has a drive unit 62a and a pair of left and right measuring units 62L and 62R located below the drive unit 62a.

[0091] The drive unit 62a is a mechanism that individually drives the left measuring unit 62L and the right measuring unit 62R to move horizontally (in the X direction and / or Z direction), move vertically (in the Y direction), rotate in the X direction, and rotate in the Y direction, respectively.

[0092] The left measuring unit 62L and the right measuring unit 62R are paired to correspond individually to the left and right eyes of the subject S. The left measuring unit 62L incorporates a left measuring optical system 65L for measuring the ocular characteristics of the left eye of the subject S. The right measuring unit 62R incorporates a right measuring optical system 65R for measuring the ocular characteristics of the right eye of the subject S. The measurement results from the measuring head 62 are transmitted to the control unit 80.

[0093] The left measuring optical system 65L and the right measuring optical system 65R each have multiple optical systems, including an anterior segment observation system, a target projection system, and a measuring optical system. Here, the anterior segment optical system is an optical system for observing the anterior segment of the eye under examination. The target projection system is an optical system for presenting various targets O, including an astigmatism test chart 45 (see Figure 5) and a radial chart 41 (see Figure 4). The measuring optical system is an optical system that includes optical elements whose power and axial direction can be changed.

[0094] The control unit 80 is an information processing device located below the eye examination table 51. Based on operation signals transmitted from the examiner controller 70 or the subject controller, the control unit 80 transmits predetermined control signals to the measurement unit 60, which includes the left measuring optical system 65L and the right measuring optical system 65R. The control unit 80 also transmits the measurement results of the eye characteristics of the subject's eye, measured by the measuring head 62, to the examiner controller 70. In this way, each part of the measurement unit 60, which has the measuring optical system, the target projection system, etc., is comprehensively controlled by the control unit 80.

[0095] The examiner controller 70 is a device that receives operations from examiner E and transmits predetermined operation signals to the control unit 80. The examiner controller 70 is configured, for example, as a tablet terminal and has a display screen 70a. That is, the examiner controller 70 has the same configuration as the examiner operation unit 32 and examiner display unit 33 of the first controller 31 in the first embodiment. Therefore, a description of the examiner controller 70 will be omitted.

[0096] Furthermore, the subject controller (not shown) is a device that receives operations from the subject S and transmits predetermined operation signals to the control unit 80. The subject controller has the same configuration as the second controller 35 in the first embodiment. Therefore, a description of the subject controller is omitted.

[0097] Furthermore, the radial chart 41 and the astigmatism test chart 45 displayed in the ophthalmic device 1A are the same as those in the first embodiment, so their description will be omitted.

[0098] In other words, the ophthalmic device 1A of the second embodiment is an ophthalmic device that integrally includes the subjective eye examination device 10, the visual target presentation device 20, and the control unit 34 of the operating device 30 as in the ophthalmic device 1 of the first embodiment.

[0099] Although the ophthalmic apparatus of this disclosure has been described above based on the first and second embodiments, the specific configuration is not limited to these embodiments. Changes and additions to the design of the ophthalmic apparatus of this disclosure are permitted as long as they do not depart from the gist of the invention as described in each claim.

[0100] In other words, in the astigmatism test chart 45, the width W1 of multiple first lines 46a, the interval W2 between the first lines 46a, the width W3 of multiple second lines 47a, and the interval W4 between the second lines 47a are all set to the same length. However, the width W1 of the first lines 46a and the interval W2 between the first lines 46a do not necessarily have to be set to the same length.

[0101] For example, as shown in the modified astigmatism test chart 45A in Figure 10, the widths W1 of the multiple first lines 46a may be set to different lengths. Also, the intervals W2 between the first lines 46a may be set to different lengths.

[0102] In the modified astigmatism test chart 45A, the widths W3 of the multiple second lines 47a and the spacing W4 between the second lines 47a are set to the same length. However, the widths W3 of the multiple second lines 47a and the spacing W4 between the second lines 47a may also be set to different lengths.

[0103] Furthermore, in the modified astigmatism test chart 45A, the width W1 of the multiple first lines 46a is set to gradually increase from one direction of alignment of the first lines 46a to the other. Similarly, the spacing W2 between the first lines 46a is also set to gradually increase from one direction of alignment of the first lines 46a to the other. However, the width W1 of the first lines 46a and the spacing W2 between the first lines 46a can each be set to any length. In other words, the width W1 of the first lines 46a and the spacing W2 between the first lines 46a do not necessarily have to increase from one direction of alignment of the lines to the other.

[0104] Furthermore, when the ophthalmic device 1 performs an astigmatism test, in step S6, the astigmatism test chart 45 is displayed with the first straight line 46a aligned with the first angle set in step S5. In other words, the astigmatism test chart 45 is displayed in a state where the rotation angle can be immediately adjusted. However, the display procedure for the astigmatism test chart 45 is not limited to this.

[0105] The control unit 34 may perform the second phase after the first phase in step S6, in which the astigmatism test chart 45 is rotated and displayed. Here, the first phase is the phase in which the astigmatism test chart 45 is rotated 360°. The second phase is the phase in which the rotation angle of the astigmatism test chart 45 is adjusted according to how the astigmatism test chart 45 appears to the subject S.

[0106] In other words, the control unit 34 first displays the astigmatism test chart 45 in the center of the target presentation area 22a. At this time, the astigmatism test chart 45 is displayed with the first straight line 41a aligned with the first angle. Next, the control unit 34 automatically rotates the astigmatism test chart 45 displayed in the target presentation area 22a 360° around the virtual center point X (first phase). The rotation direction and rotation speed of the astigmatism test chart 45 in the first phase can be set arbitrarily.

[0107] Then, when the astigmatism test chart 45 has rotated 360°, the control unit 34 temporarily stops the rotation of the astigmatism test chart 45. At this time, the astigmatism test chart 45 is in a state where the first straight line 41a is aligned with the first angle. Subsequently, the control unit 34 rotates the astigmatism test chart 45 based on the subject S's operation to the second controller 35 (second phase).

[0108] Here, when subject S simultaneously compares how two groups of lines appear, if the rotation angle of the astigmatism test chart 45 is small or the rotation speed is too slow, subject S may not be able to recognize the change in how the first target 46 and the second target 47 appear due to the rotation of the astigmatism test chart 45. Therefore, by performing the above first phase before the second phase, the ophthalmic device 1 can make subject S aware that the appearance of the first target 46 and the second target 47 changes as the astigmatism test chart 45 rotates, that is, that the appearance of the first target 46 and the second target 47 differs depending on the rotation angle of the astigmatism test chart 45.

[0109] This makes it easier for the subject S to recognize the changes in the appearance of the first target 46 and the second target 47 as the astigmatism test chart 45 rotates. Furthermore, the ophthalmic device 1 can improve the accuracy of acquiring the axis angle of the astigmatism axis.

[0110] Furthermore, the ophthalmic device 1 displays the radial chart 41 on the display unit 22. The ophthalmic device 1 then starts rotating the astigmatism test chart 45 from a position where the first straight line 41a aligns with the first angle (the radial line 42 that the subject S most clearly perceived). However, the radial chart 41 does not necessarily have to be displayed. In other words, the ophthalmic device 1 only needs to be able to display the astigmatism test chart 45.

[0111] Furthermore, the ophthalmic device 1 adjusts the power of the cylindrical lens so that the first target 46 and the second target 47 appear to be roughly the same in appearance while the astigmatism test chart 45 is displayed. In other words, the subject S adjusts the power of the cylindrical lens while viewing the astigmatism test chart 45, and as a result, the degree of astigmatism is obtained. However, the target O that the subject S is shown when adjusting the power of the cylindrical lens does not have to be the astigmatism test chart 45.

[0112] The ophthalmic device 1 may, for example, adjust the power of the cylindrical lens so that all radial lines 42 appear to be roughly the same when the radial chart 41 is displayed on the display unit 22. In other words, it is not always necessary to use the astigmatism test chart 45 when obtaining the degree of astigmatism.

[0113] Furthermore, in the astigmatism test chart 45, each of the multiple first lines 46a and multiple second lines 47a has a brightness in the width direction that changes according to a sine function, resulting in a straight line with an indistinct outline. However, if the first lines 46a and second lines 47a are to be straight lines with an indistinct outline, the brightness of the first lines 46a and second lines 47a does not necessarily have to change according to a sine function. In other words, the brightness of the first lines 46a and second lines 47a only needs to be higher at the edges on both sides than in the middle part in the width direction. As a result, the first lines 46a and second lines 47a become straight lines with an indistinct outline.

[0114] Furthermore, some of the multiple first lines 46a and multiple second lines 47a may have lines with indistinct outlines. In other words, the first target 46 may consist of lines with clear outlines and lines with indistinct outlines. Similarly, the second target 47 may consist of lines with clear outlines and lines with indistinct outlines. Moreover, all of the multiple first lines 46a and multiple second lines 47a may be lines with clear outlines. Note that a "line with a clear outline" is a line whose brightness does not change in the width direction, that is, a line whose brightness is constant throughout its entirety.

[0115] Furthermore, in the astigmatism test chart 45, the boundary between the first region 48 and the second region 49 almost coincides, and some of the first lines 46a have both ends that are almost continuous with either of the second lines 47a. However, the second region 49 only needs to surround the entire circumference of the first region 48. For this reason, there may be a gap between the first region 48 and the second region 49 where the target O is not displayed. In this case, the first line 46a and the second line 47a are discontinuous.

[0116] Furthermore, the subject operation unit 36 ​​of the second controller 35 has a dial member 36a and a push button 36b. However, the subject operation unit 36 ​​only needs to be able to receive operations from the subject S and transmit operation signals corresponding to the received operations. In other words, the subject operation unit 36 ​​does not necessarily need to have a dial member 36a.

[0117] Furthermore, the following is disclosed in relation to the above description of embodiments and modifications. (1) A display unit capable of displaying an astigmatism test chart for obtaining the astigmatism axis angle of the subject, and a control unit that controls the display unit to rotate and display the astigmatism test chart within the display unit, The astigmatism test chart comprises a first target consisting of a plurality of first lines arranged parallel to each other at predetermined intervals, and a second target consisting of a plurality of second lines arranged parallel to each other at predetermined intervals and extending in a direction perpendicular to the first lines. The first target is displayed in a circular first region, and the second target is displayed in a ring-shaped second region surrounding the first region. An ophthalmic device characterized by the following features. (2) In the ophthalmic device described in (1) above, The system includes a controller for the subject that accepts input from the subject, The control unit modifies at least one of the following based on the subject's operation received by the subject controller: the width of the multiple first lines, the spacing between the first lines, the width of the multiple second lines, and the spacing between the second lines. An ophthalmic device characterized by the following features. (3) In the ophthalmic device described in (1) or (2) above The astigmatism test chart shows that the contours of at least a portion of the first and second lines are unclear. An ophthalmic device characterized by the following features. (4) In the ophthalmic device described in (3) above, The astigmatism test chart shows that the brightness in the width direction of at least a portion of the first and second lines changes according to a sine function. An ophthalmic device characterized by the following features. (5) In an ophthalmic device described in any one of (1) to (4) above, The measuring optical system is positioned between the eye under examination and the astigmatism test chart and includes an optical element whose power and axial direction can be changed, The control unit controls the display unit to rotate and display the astigmatism test chart within the display unit, and stops the rotation of the astigmatism test chart when the subject can clearly see the first target. The measuring optical system is controlled to align the axial direction of the optical element with a predetermined angle set based on the tilt direction of the first target when its rotation has stopped, and the power of the optical element is changed so that the subject can clearly see the second target. An ophthalmic device characterized by the following features. (6) In an ophthalmic device described in any one of (1) to (5) above, The control unit causes the display unit to display a radial chart having a plurality of radial lines extending in the radial direction. The rotation of the astigmatism test chart is started from a position where the first straight line aligns with the radial line clearly visible to the subject. An ophthalmic device characterized by the following features. (7) In the ophthalmic device described in (6) above, The control unit displays the radial chart using the display unit, and at the same time displays a marker near the tip of any of the multiple radial lines. The marker is moved sequentially until it is fixed near the tip of the radial line that is clearly visible to the subject. An ophthalmic device characterized by the following features. (8) In an ophthalmic device described in any one of (1) to (7) above, When the control unit rotates and displays the astigmatism test chart on the display unit, it performs a first phase of rotating the astigmatism test chart 360° before a second phase of adjusting the rotation angle of the astigmatism test chart according to how the astigmatism test chart appears to the subject. An ophthalmic device characterized by the following features. (9) In an ophthalmic device described in any one of (1) to (8) above, The subject controller includes a dial member that is rotated by the subject, The control unit controls the display unit based on the rotation angle of the dial member. An ophthalmic device characterized by the following features. (10) A control method for an ophthalmic apparatus comprising: a display unit capable of displaying an astigmatism test chart for obtaining the astigmatism axis angle of a subject; and a control unit that controls the display unit to rotate and display the astigmatism test chart within the display unit, The astigmatism test chart display step includes displaying the astigmatism test chart on the display unit, the astigmatism test chart having a first target consisting of a plurality of first lines arranged parallel to each other at predetermined intervals, and a second target consisting of a plurality of second lines arranged parallel to each other at predetermined intervals and extending in a direction perpendicular to the first lines, In the astigmatism test chart display step, the first target is displayed in a circular first region, and the second target is displayed in a ring-shaped second region surrounding the first region. A method for controlling an ophthalmic device, characterized by the features described above. (11) In the control method of the ophthalmic device described in (10) above, The ophthalmic device includes a patient controller that accepts operations from the patient, The subject controller includes a line spacing modification step that modifies at least one of the widths of a plurality of first lines, the spacing between the first lines, the widths of a plurality of second lines, and the spacing between the second lines, based on the subject's operation received by the subject. A method for controlling an ophthalmic device, characterized by the features described above. (12) In the control method of the ophthalmic device described in (10) or (11) above, The ophthalmic device is positioned between the eye to be examined and the astigmatism test chart and includes a measuring optical system that includes an optical element whose power and axial direction can be changed. A rotation display step in which the astigmatism test chart is rotated and displayed within the display unit, A stopping step in which the rotation of the astigmatism test chart is stopped while the subject is clearly viewing the first target, An axial adjustment step to align the axial direction of the optical element with a predetermined angle set based on the tilt direction of the first target when its rotation has stopped, The step includes adjusting the power of the optical element so that the subject can clearly see the second target, with the axial direction of the optical element aligned with the predetermined angle. A method for controlling an ophthalmic device, characterized by the features described above. [Explanation of Symbols]

[0118] 1, 1A ophthalmological equipment 10. Subjective optometry device (measuring optical system) 10L optometry unit 10R optometry unit 20. Visual Target Presentation Device 22 Display section 22a Target presentation area 30 Operating device 31. First Controller 32 Examiner operation section 33 Examiner display 34, 80 Control Unit 35. Second controller (controller for the subject) 36. Patient's control unit 36a Dial member 36b Push button 37 Second Control Unit 41 Radial chart 41a 1st straight line 42 Radial lines 43 Landmarks 45, 45A Astigmatism Test Chart 46 1st visual target 46a 1st straight line 47 Second visual target 47a 2nd straight line 48 First area 49 Second area E Examiner S Subject

Claims

1. The system comprises a display unit capable of displaying an astigmatism test chart for obtaining the astigmatism axis angle of the subject, and a control unit that controls the display unit to rotate and display the astigmatism test chart within the display unit. The astigmatism test chart comprises a first target consisting of a plurality of first lines arranged parallel to each other at predetermined intervals, and a second target consisting of a plurality of second lines arranged parallel to each other at predetermined intervals and extending in a direction perpendicular to the first lines. The first target is displayed in a circular first region, and the second target is displayed in a ring-shaped second region surrounding the first region. An ophthalmic device characterized by the following features.

2. In the ophthalmic device described in claim 1, The system includes a controller for the subject that accepts input from the subject, The control unit modifies at least one of the following based on the subject's operation received by the subject controller: the width of the plurality of first lines, the spacing between the first lines, the width of the plurality of second lines, and the spacing between the second lines. An ophthalmic device characterized by the following features.

3. In an ophthalmic device according to claim 1 or claim 2 The astigmatism test chart shows that the contours of at least a portion of the first and second lines are unclear. An ophthalmic device characterized by the following features.

4. In the ophthalmic device described in claim 3, The astigmatism test chart shows that the brightness in the width direction of at least a portion of the first and second lines changes according to a sine function. An ophthalmic device characterized by the following features.

5. In the ophthalmic device described in claim 1 or claim 2, The measuring optical system is positioned between the eye under examination and the astigmatism test chart and includes an optical element whose power and axial direction can be changed, The control unit controls the display unit to rotate and display the astigmatism test chart within the display unit, and stops the rotation of the astigmatism test chart when the subject can clearly see the first target. The measuring optical system is controlled to align the axial direction of the optical element with a predetermined angle set based on the tilt direction of the first target when its rotation has stopped, and the power of the optical element is changed so that the subject can clearly see the second target. An ophthalmic device characterized by the following features.

6. In the ophthalmic device described in claim 5, The control unit causes the display unit to display a radial chart having a plurality of radial lines extending in the radial direction. The rotation of the astigmatism test chart is started from a position where the first straight line aligns with the radial line clearly visible to the subject. An ophthalmic device characterized by the following features.

7. In the ophthalmic device described in claim 6, The control unit displays the radial chart using the display unit, and at the same time displays a marker near the tip of any of the multiple radial lines. The markers are moved sequentially until they are fixed near the tip of the radial line that is clearly visible to the subject. An ophthalmic device characterized by the following features.

8. In the ophthalmic device described in claim 5, When the control unit rotates and displays the astigmatism test chart on the display unit, it performs a first phase of rotating the astigmatism test chart 360° before a second phase of adjusting the rotation angle of the astigmatism test chart according to how the astigmatism test chart appears to the subject. An ophthalmic device characterized by the following features.

9. In the ophthalmic device described in claim 1, The subject controller includes a dial member that is rotated by the subject, The control unit controls the display unit based on the rotation angle of the dial member. An ophthalmic device characterized by the following features.

10. A control method for an ophthalmic device comprising: a display unit capable of displaying an astigmatism test chart for obtaining the astigmatism axis angle of a subject; and a control unit that controls the display unit to rotate and display the astigmatism test chart within the display unit, The astigmatism test chart display step includes displaying the astigmatism test chart on the display unit, the astigmatism test chart having a first target consisting of a plurality of first lines arranged parallel to each other at predetermined intervals, and a second target consisting of a plurality of second lines arranged parallel to each other at predetermined intervals and extending in a direction perpendicular to the first lines, In the astigmatism test chart display step, the first target is displayed in a circular first region, and the second target is displayed in a ring-shaped second region surrounding the first region. A method for controlling an ophthalmic device, characterized by the features described above.

11. In the control method for an ophthalmic device described in claim 10, The ophthalmic device includes a patient controller that accepts operations from the patient, The subject controller includes a line spacing changing step which, based on the subject's operation received by the subject, changes at least one of the widths of the multiple first lines, the spacing between the first lines, the widths of the multiple second lines, and the spacing between the second lines. A method for controlling an ophthalmic device, characterized by the features described above.

12. In a control method for an ophthalmic device according to claim 10 or claim 11, The ophthalmic device is positioned between the eye under examination and the astigmatism test chart and includes a measuring optical system that includes an optical element whose power and axial direction can be changed. A rotation display step in which the astigmatism test chart is rotated and displayed within the display unit, A stopping step in which the rotation of the astigmatism test chart is stopped while the subject is clearly viewing the first target, An axial adjustment step to align the axial direction of the optical element with a predetermined angle set based on the tilt direction of the first target when its rotation has stopped, The step includes adjusting the power of the optical element so that the subject can clearly see the second target, with the axial direction of the optical element aligned with the predetermined angle. A method for controlling an ophthalmic device, characterized by the features described above.

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