JP2007325953A - Optometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optometer capable of shortening the optometry time. <P>SOLUTION: This optometer is provided with: an indicator projecting optical system projecting an indicator on a subject's eye; a cross cylinder lens forming a pair of projection images of the indicator by changing the astigmatic axial angle under a condition of generating a prescribed astigmatic degree; an operation means for inputting a comparison result of viewing condition of the projection images; a measurement means measuring the astigmatic axial angle of the subject's eye based on the astigmatic axial angle; a setting means setting a displacement from an objective value of the astigmatic axial angle; and a control means, when a predetermined direction is input, changing the absolute value of the displacement to a present value or less, reversing the positive/negative of the displacement, adding the displacement after the change to the objective value of the astigmatic axial angle, and changing the astigmatic axial angle of the cross cylinder lens to the added value. The measurement means measures the astigmatic axial angle when the acuity of the pair of projection images become substantially equal to each other via the change of the astigmatic axial angle by the control means, as the astigmatic axial angle of the subject's eye. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optometry apparatus capable of performing a cross cylinder test for examining astigmatism of an eye to be examined.

  2. Description of the Related Art An optometry apparatus for performing an optometry measurement that can perform a cross cylinder test is known. For example, the optometry apparatus described in Patent Document 1 is equipped with operation means such as a joystick lever and a computer program for automatically advancing the optometry, and can perform objective optometry at the same time on both eyes and by screen and voice. The subject can perform subjective optometry according to the navigation. The cross-cylinder test is performed in the flow of such inspection.

  The optometry apparatus of Patent Literature 1 is configured to provide a practice screen for practicing an operation method in an examination before actually performing the examination. On this practice screen, cross-cylinder test is also practiced. In the cross-cylinder test, a target S (referred to as a cross-cylinder test chart or the like) as shown in FIG. Although the astigmatism of the eye to be examined is inspected by making the examiner compare and judge, the difference in the appearance to be compared is not so clear. Therefore, on the practice screen, the difference in typical appearance when the astigmatic axis angle is switched is exaggerated, one projection image is clearly displayed, and the other projection image is displayed in a blurred state. It is designed to promote understanding of the contents of the cylinder test and the operation method.

  However, if practice is performed before the inspection, a certain amount of time has passed before the actual start of the cross cylinder test, so there is a risk that the inspection content and operation method may be forgotten. In addition, since the practice itself takes time, there is also a problem that the inspection time per subject becomes longer.

  In addition, since the difference in the appearance of the target to be compared is not clear in the cross cylinder test and it is difficult for the subject to make a quick decision, the cross cylinder test itself may take a long time. It was. In particular, the astigmatic axis angle may be inspected with an unnecessarily high measurement accuracy, which hinders the smooth implementation of the cross cylinder test. Furthermore, since the astigmatic axis angle measurement by the cross cylinder test is for comparing the appearance of the pair of projection images of the cross cylinder test chart S, the measurement may be terminated in a state where the projection images are not clearly seen. For this reason, the response at the final stage of the test becomes ambiguous, and the inspection time may be prolonged.

JP 2004-180955 A (claims, specification paragraphs [0030), [0039]-[0047])

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optometry apparatus capable of smoothly performing a cross cylinder test and shortening an inspection time.

  In order to achieve the above object, an invention according to claim 1 is an optical system that projects a target for cross cylinder testing onto an eye to be examined, and an optical system that is disposed on the optical axis of the optical system, and has a predetermined astigmatism power. A cross-cylinder lens that forms a pair of projected images of the target by switching the astigmatic axis angle in the generated state, and an operation means for inputting a comparison result of the appearance of the pair of projected images of the target; Measurement means for measuring the astigmatism axis angle of the eye to be examined based on the astigmatism axis angle of the cross cylinder lens, setting means for setting a displacement amount from an objective value of the astigmatism axis angle, and predetermined via the operation means When the given direction is input, the absolute value of the displacement amount is changed to a current value or less and the positive / negative of the displacement amount is reversed, and the changed displacement amount is added to the objective value of the astigmatic axis angle, The cross cylinder is added to the added value. Control means for changing the astigmatism axis angle of the lens, and the measurement means is configured to change the astigmatism when the clarity of the pair of projection images becomes substantially equal through the change of the astigmatism axis angle by the control means. An axis angle is measured as an astigmatic axis angle of the eye to be examined.

  Further, the invention according to claim 2 is the optometry apparatus according to claim 1, wherein the control means determines a predetermined astigmatism axis angle through the operation means for an astigmatic axis angle given as an initial value. Is inputted, the absolute value of the displacement amount given in relation to the initial value is decreased and the sign of the displacement amount is reversed.

  The invention according to claim 3 is the optometry apparatus according to claim 1, wherein the control means receives a predetermined direction via the operation means, and the current value of the displacement amount. When the previous value of the displacement amount is positive and negative and the absolute value is the same, it is changed by decreasing the absolute value of the displacement amount, and the changed displacement amount is added to the objective value of the astigmatic axis angle. It is characterized by.

  Further, the invention according to claim 4 is the optometry apparatus according to claim 1, wherein the setting means includes an astigmatism axis angle corresponding to an astigmatism value of the astigmatism degree of the eye to be measured measured in advance. The amount of displacement from the perception value is acquired, the objective value of the astigmatism axis angle is displaced by the acquired amount of displacement, and one of the pair of projection images is clearly visually recognized, and the other is blurred. The astigmatic axis angle of the cross cylinder lens for visual recognition is obtained and set as an initial value in the astigmatic axis angle measurement, and the control means changes the astigmatic axis angle of the cross cylinder lens starting from the initial value. It is characterized by that.

  The invention according to claim 5 is the optometry apparatus according to claim 1, wherein the storage means determines the amount of displacement from the objective value of the astigmatic axis angle in advance as an objective value of the astigmatism degree. It is characterized in that it is stored in correspondence with.

  The invention according to claim 6 is the optometry apparatus according to claim 1, wherein according to the correspondence stored in the storage means, the absolute value of the objective value of the astigmatism degree increases. Therefore, the amount of displacement from the objective value of the astigmatic axis angle is small.

  According to the optometry apparatus according to the present invention, based on the astigmatism power and the astigmatism axis angle of the eye to be measured in advance, one of the pair of projected images of the cross cylinder test target is clearly visible. The first stage of the actual cross cylinder test is provided with an initial value setting means for obtaining the astigmatic axis angle of the cross cylinder lens for visually observing the other in a blurred state and setting it as an initial value in the astigmatic axis angle measurement. Thus, by comparing and judging a clear projected image and a blurred projected image, the contents of the test can be understood and the operation method of the operation means can be practiced. Therefore, the understanding of the cross-cylinder test and the practice of the operation method can be carried out in an integrated manner with the actual inspection, so the test content and operation method once understood will not be forgotten over time, and the cross-cylinder test Can be carried out smoothly, and the inspection time can be shortened. Further, since it is not necessary to spend time before the inspection to practice the cross cylinder test as in the prior art, the inspection time including the practice time can be shortened as a whole.

  Further, since the astigmatism axis angle can be measured with an allowable error corresponding to the objective value of the astigmatism power of the eye to be examined, the astigmatism axis angle is not inspected with an unnecessarily high measurement accuracy. Accordingly, the inspection can be performed smoothly and the inspection time can be shortened.

  An example of a preferred embodiment of an optometry apparatus according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an external side view of an optometry apparatus 2 according to this embodiment, and FIG. 2 is an external perspective view thereof. 3 to 8 show the configuration of the optical system provided in the optometry apparatus 2, and FIGS. 9 and 10 show the configuration of the control system of the optometry apparatus 2. 11 to 15 show data used in the cross cylinder test by the optometry apparatus 2. FIG. 16 shows a cross cylinder test chart which is a target for cross cylinder test.

[Device configuration]
As shown in FIG. 1, the optometry apparatus 2 of the present embodiment is used by being placed on an optometry table 1 whose height can be adjusted up and down. The subject 4 is inspected while sitting on an optometry chair 3 provided together with the optometry table 1.

  Further, as shown in FIG. 2, a column 64s is erected on the optometry table 1, and a liquid crystal monitor 64q is provided at the upper end of the column 64s.

  As shown in FIGS. 1 and 2, the optometry apparatus 2 includes a pedestal portion 5a, a drive mechanism box 5b disposed on the pedestal portion 5a, and a pair of left and right optical heads incorporating a measurement optical system to be described later. 5l and 5r, and a face receiving device 6 for fixedly arranging the face of the subject 4 at the time of examination. The optical head portions 5l and 5r are respectively supported by the columns 5p and 5q, and are independently driven three-dimensionally by the drive mechanism box 5b. Liquid crystal monitors 64l and 64r are provided on the front surfaces of the optical head portions 5l and 5r, respectively. On the liquid crystal monitors 64l and 64r, an anterior ocular segment image and a fundus reflection image of the eye to be examined during the examination are displayed. The examiner or assistant can confirm whether or not the examination is properly performed by looking at the anterior segment image displayed on the liquid crystal monitors 64l and 64r.

  The face receiving device 6 includes a pair of left and right supports 6a and 6b, a forehead support 6c supported by a member connecting the upper ends of the supports 6a and 6b, and a chin rest 6d disposed below the forehead support 6c. Is provided. The forehead pad 6c is a member with which the forehead of the subject 4 abuts at the time of examination, is formed in an arc shape in order to improve the adhesion to the forehead, and can be adjusted in the front-rear direction. It has become. The chin rest 6d is a member on which the chin of the subject 4 is placed at the time of inspection, and the position thereof can be adjusted in the vertical direction by operating the pair of left and right knobs 6e. The subject 4 places the chin on the chin rest 6d and fixes the position of the face by bringing the forehead into contact with the forehead pad 6c and starts the examination.

  The drive mechanism box 5b incorporates an XYZ drive mechanism for independently and three-dimensionally driving the optical head portions 5l and 5r supported by the columns 5p and 5q. Although not shown in the drawing, this XYZ drive mechanism has a known configuration using, for example, a pulse motor or a feed screw.

  Further, in the drive mechanism box 5b, there is provided a rotation drive mechanism for independently rotating the optical head portions 5l and 5r in the horizontal direction. For example, the rotation drive mechanism rotates the optical head portions 5l and 5r by transmitting the rotation driving force of the pulse motor to the respective pillars 5p and 5q via a gear. As a result, the optical head portions 5l and 5r are rotated in opposite directions around the eyeball rotation points of the left and right eyes of the subject 4, respectively.

  Optical systems as shown in FIGS. 3 to 7 are stored in the optical head portions 5l and 5r. The optical head units 5l and 5r are configured to perform objective refraction measurement and subjective refraction measurement of both eyes of the subject 4 by operating the optical system.

  The pedestal portion 5a is provided with a joystick lever (sometimes simply referred to as a lever) 6h. A button 6g is provided above the lever 6h. The subject 4 performs an examination by appropriately operating the lever 6h and the button 6g.

[Configuration of optical system]
The configuration of the measurement optical system stored in the optical head units 5l and 5r will be described in detail. First, as shown in FIGS. 3 to 5, the optical head unit 51 for measuring the left eye of the subject 4 includes an anterior ocular segment imaging optical system 30L, an XY alignment optical system 31L, and target projection optics. A system 32L and a refractive power measurement optical system 33L are provided. Further, as shown in FIGS. 3, 6, and 7, the optical head unit 5 r that measures the right eye of the subject 4 includes an anterior segment imaging optical system 30 </ b> R, an XY alignment optical system 31 </ b> R, and a visual field. A standard projection optical system 32R and a refractive power measurement optical system 33R are provided. The measurement optical system of the optical head unit 5l and the measurement optical system of the optical head unit 5r are configured symmetrically. Hereinafter, unless otherwise specified, the measurement optical system of the left-eye measurement optical head 5l will be described.

  The anterior ocular segment imaging optical system 30L provided in the optical head unit 51 includes an anterior ocular segment illumination optical system 34 and an imaging optical system 35.

  As shown in FIGS. 4 and 5, the anterior ocular segment illumination optical system 34 is emitted from the light source 36 for illuminating the anterior segment of the left eye (examined eye EL) of the subject 4 and the light source 36. A diaphragm 36a for limiting the cross-sectional area of the luminous flux and a projection lens 37 for projecting the luminous flux that has passed through the diaphragm 36a onto the anterior eye portion of the eye EL to be examined.

  The photographing optical system 35 includes a prism P on which reflected light from the anterior eye portion of the eye EL illuminated by the anterior eye illumination optical system 34 is incident, and a light beam reflected by the reflecting surface of the prism P. Is incident on the objective lens 38, the dichroic mirror 39, the aperture 40, the dichroic mirror 41, the relay lenses 42 and 43, the dichroic mirror 44, and the CCD lens 45 that forms a light beam on the light receiving surface of the CCD 46. I have.

  The XY alignment optical system 31L is an optical system for performing alignment in the X and Y directions of the optical system of the optical head unit 51 with respect to the eye EL to be examined, and includes an alignment illumination optical system 47 that projects a light beam for alignment onto the eye EL to be examined. It includes a photographing optical system 35 as an alignment light receiving optical system that receives the reflected light. Here, the left-right direction as viewed from the subject 4 is the X direction, and the up-down direction is the Y direction. The depth direction of the optometry apparatus 2 when viewed from the subject 4 is the Z direction.

  As shown in FIGS. 3 and 4, the alignment illumination optical system 47 includes an illumination light source 48 that emits a light beam for alignment in the XY directions, a diaphragm 49 as an alignment target, a relay lens 50, and a dichroic mirror 41. A diaphragm 40, a dichroic mirror 39, an objective lens 38, and a prism P are provided.

  The optotype projection optical system 32L includes a liquid crystal display 53 that displays various optometrists (charts) for optometry, a half mirror 54 that reflects light from the liquid crystal display 53, a collimator lens 55, and an oblique position. Rotary prisms 55A and 55B for adjusting the prism power and the prism base direction in the examination, the reflection mirror 56, a moving lens 57 used when the eye EL is fixed and fogged, and relay lenses 58 and 58 ' , A variable cross cylinder lens (VCC lens) 59 for adjusting the astigmatism power and the astigmatic axis angle of the subject eye EL by the cross cylinder test, the reflection mirror 60, the dichroic mirrors 61 and 39, the objective lens 38, and the prism P And.

  The liquid crystal display 53 includes a fixation chart composed of a landscape chart, a vision chart such as a Landolt ring for vision test, a cross cylinder test chart S (see FIG. 16), a radiation chart for astigmatism examination, and a cross for oblique examination. Targets such as charts and red-green test charts are selectively displayed. Instead of the liquid crystal display 53, a known target presentation unit that presents a target by illuminating the turret board on which a plurality of targets are formed from behind may be used.

  The rotary prisms 55A and 55B are independently rotated by driving a pulse motor or the like. When the rotary prisms 55A and 55B are rotated in opposite directions, the prism power is continuously changed, and when the rotary prisms 55A and 55B are rotated integrally in the same direction, the prism base direction is continuously changed.

  As shown in FIG. 8, the VCC lens 59 includes a cylindrical lens 59A having a convex surface (positive power) and a cylindrical lens 59B having a concave surface (negative power). The cylindrical lenses 59A and 59B are driven by a driving device such as a pulse motor, and are independently rotated about the optical axis of the target projection optical system 32L. When the cylindrical lenses 59A and 59B are rotated in opposite directions, the astigmatism power is changed, and when the cylindrical lenses 59A and 59B are rotated integrally in the same direction, the astigmatic axis angle is changed.

  In particular, the VCC lens 59 reverses the astigmatism axis angle in a state where a predetermined astigmatism power is generated at each stage of the cross cylinder test (by switching between the axial direction of the positive power and the axial direction of the negative power). A pair of projected images of the cross cylinder test chart S (see FIG. 16) is formed. The pair of projection images are projected onto the eye to be examined EL and ER while being switched alternately. The subject compares the appearance of the pair of projection images, and inputs a response by operating the lever 6h or the like to determine which projection image can be clearly seen.

  The moving lens 57 is driven by a driving device such as a pulse motor and is moved in the optical axis direction of the target projection optical system 32L, thereby changing the sphericity added to the eye EL to be examined. For example, by moving the moving lens 57 in the direction of the optical axis by the amount of movement corresponding to the refractive power of the eye EL to be examined, fixation cloud for the eye EL to be examined is performed.

  As shown in FIG. 5, a fusion target projection optical system 32L ′ is provided in the transmission direction of the half mirror 54 of the target projection optical system 32L. The fusion target projection optical system 32L ′ includes an LED 53A that emits illumination light, a collimator lens 53B, a fusion frame chart 53D, and a total reflection mirror 53E. For example, the fusion frame chart 53D includes a light shielding member in which a square-shaped transmission window (fusion frame) is formed. The collimator lens 53B is provided with a diffusing surface so that the light from the LED 53A is diffused to uniformly illuminate the fusion frame chart 53D.

  In the present embodiment, the fusion target projection optical system 32L ′ independent from the target projection optical system 32L is provided, but a fusion frame may be displayed on the liquid crystal display 53.

  As shown in FIG. 5, the refractive power measurement optical system 33L receives the measurement light beam projection optical system 62 that projects a light beam for objective measurement onto the eye E and the reflected light of the projection light from the eye EL. And a measuring beam receiving optical system 63.

  The measurement light beam projection optical system 62 includes a measurement light source 64 such as an infrared LED, a collimator lens 65, a conical prism 66, a ring target 67, a relay lens 68, a ring-shaped aperture 69, and a through hole in the center. A perforated prism 70 formed with 70a, dichroic mirrors 61 and 39, an objective lens 38, and a prism P are included.

  The measurement light beam receiving optical system 63 includes a prism P on which reflected light from the fundus oculi Ef of the eye to be examined EL is incident, an objective lens 38, dichroic mirrors 39 and 61, a through hole 70a of the perforated prism 70, The reflecting mirror 71, the relay lens 72, the moving lens 73, the reflecting mirror 74, the dichroic mirror 44, the CCD lens 45, and the CCD 46 are included.

  The optometry apparatus 2 of the present embodiment is controlled by a control system described later, and the alignment of the optical system of the optical heads 5l and 5r with respect to the subject's eyes EL and ER, objective optometry, subjective optometry, and binocular balance test Etc. are to be executed automatically. In the subjective optometry, a value (objective value) obtained by the objective optometry is used. In particular, in the cross-cylinder test in the subjective optometry, the astigmatism power and the astigmatic axis angle obtained by the objective optometry are used.

[Control system configuration and processing details]
Next, the configuration of the control system of the optometry apparatus 2 according to the present embodiment and the processing content of the present embodiment will be described with reference to FIGS. The block diagram shown in FIG. 9 represents the schematic configuration of the main part of the control system of the optometry apparatus 2, and the block diagram shown in FIG. 10 represents the schematic configuration of the part of the control system that executes the processing according to the present invention. . 11 to 15 show cross cylinder test data used in the execution of the cross cylinder test.

  As shown in FIG. 9, the control system of the optometry apparatus 2 is configured around a control unit 80 that controls each part of the apparatus. The control unit 80 is stored in, for example, the pedestal unit 5a of the optometry apparatus 2, and a non-volatile storage device such as a ROM storing a computer program for optometry including a control program for processing as described later, and the computer And an arithmetic control processor such as a CPU for executing the program. In particular, the control unit 80 constitutes a “control unit” that performs various controls in the cross cylinder test.

  A computer device (not shown) is connected to the optometry apparatus 2. The computer device is used as a console of the optometry apparatus 2 and is used for accumulating and managing examination results by the optometry apparatus 2. Note that the CPU and the storage device of the computer device can be configured as the control unit 80.

  The control unit 80 controls the operation of each of the optical head units 5l and 5r. Specifically, the control unit 80 includes an XYZ driving mechanism 81L that three-dimensionally drives the left optical head unit 51 in the XYZ directions, and a rotation driving mechanism 82L that rotationally drives the optical head unit 51 in the horizontal direction. Control each one. Similarly, the control unit 80 controls an XYZ drive mechanism 81R that three-dimensionally drives the right optical head unit 5r in the XYZ directions and a rotary drive mechanism 82R that drives the optical head unit 5r to rotate in the horizontal direction. To do.

  The control unit 80 controls the operation of the optical system stored in the optical head units 5l and 5r. For example, display control of the liquid crystal display 53, operation control of the moving lens driving units 83L and 83R that drive the moving lens 57 in the optical axis direction, and rotation of the VCC lens 59 around the optical axes of the target projection optical systems 32L and 32R. Operation control of the VCC lens driving units 84L and 84R to be driven, operation control of the prism driving units 85L and 85R that rotationally drive the rotary prisms 55A and 55B around the optical axis, and the like are executed.

  Further, the control unit 80 performs display control of the liquid crystal monitor 64q (see FIG. 2), output control of the audio output unit 86, and the like. Here, the audio output unit 86 outputs audio information such as audio navigation for automatically advancing optometry.

  In addition to the above-described control, the control unit 80 controls all operations of the optometry apparatus 2 such as control of turning on / off operations of the light source 36, the illumination light source 48, the LED 53A, and the like, and image processing on an image photographed by the CCD 46. Perform data processing.

  FIG. 10 is a block diagram showing details of a part of the control system shown in FIG. 9, and shows a configuration for executing processing characteristic of the present invention. The joystick lever 6h and the button 6g constitute an operating means 110 that is operated to input a comparison result of the appearance of a pair of projected images of the cross cylinder test chart S.

  The control unit 80 includes a storage unit 100, an initial value setting unit 101, an error setting unit 102, a determination unit 103, an optical head unit control unit 104, and an output control unit 105.

  The operations of the initial value setting unit 101, the error setting unit 102, and the determination unit 103 will be described later. The optical head part control means 104 controls each part of the optical head parts 5l and 5r (particularly the liquid crystal display 53 and the VCC lens driving mechanisms 84L and 84R). The output control means 105 performs display output control by the liquid crystal monitors 64l and 64r, in addition to display output control by the liquid crystal monitor 64q and audio output control by the audio output unit 86.

  The storage means 100 is composed of a nonvolatile storage device such as a ROM, and the test results of the eye EL and ER to be examined (especially the astigmatic values of the astigmatism power and the astigmatism axis angle) and the cross cylinder test shown in FIGS. Various optometry data including optometry data, optometry control programs, and the like are stored in advance.

  The cross cylinder test data shown in FIG. 11 is information that is referred to in order to set the value (initial value) of the astigmatic axis angle that is applied in the first stage in the cross cylinder test for the eye to be examined EL and ER. Hereinafter, this data is referred to as initial value setting data.

  This initial value setting data includes the amount of angle shift from the astigmatism axis angle corresponding to the astigmatism power objective value. More specifically, the angle shift amount when the objective value of the astigmatism power is −0.25 diopter (D) is 40 °, and the angle when the objective value of the astigmatism power is −0.50 D. When the shift amount is 30 °, the angle shift amount when the objective value of the astigmatism power is −0.75 to 1.00D is 25 °, and the objective value of the astigmatism power is −1.25D The angle shift amount is 20 °, the angle shift amount when the objective value of the astigmatism power is −1.50 to 2.00D is 15 °, and the objective value of the astigmatism power is −2.25. When the angle shift amount is 3.75D, the angle shift amount is 10 °, and when the astigmatism power objective value is −4.00 to 7.00D, the angle shift amount is 5 °, and the astigmatism power objective value. Is 3 ° when the angle is −7.25 to 8.00D.

  The angle shift amount for each astigmatism power defined in the initial value setting data in FIG. 11 is a value that makes one of the pair of projection images of the cross cylinder test chart S clearly visible and the other visually blurred. Is set to For example, in the case of weak astigmatism with an astigmatism frequency of −0.25D, when the astigmatism axis angle of the eye to be examined is shifted by about 40 °, one projected image is clearly recognized and the other is visually recognized in a blurred state. Further, in the case of strong astigmatism with an astigmatism power of −8.00D, one projection image is clearly visible and the other is visually blurred even when shifted from the astigmatism power of the eye to be examined by about 3 °. . In consideration of the fact that recent objective optometry has high measurement accuracy and that the true astigmatism axis angle of the eye to be examined is unknown before the cross cylinder test, in this embodiment, the astigmatism axis angle is The shift amount from the objective value is used to set the initial value.

  Here, an initial value setting process of the cross cylinder test using the initial value setting data will be described. This initial value setting process is executed by the initial value setting means 101 of the control unit 80. The initial value setting means 101 acquires the shift amount of the astigmatic axis angle corresponding to the astigmatism value of the astigmatism power of the eye EL and ER measured in advance from the initial value setting data in FIG. Then, an angle obtained by displacing the objective value of the astigmatic axis angle of the eye to be examined EL and ER by the acquired shift amount is set as an initial value of the cross cylinder test.

  For example, when the astigmatism value of the eye to be examined is −0.25D and the astigmatism axis angle is 30 °, referring to the initial value setting data corresponds to the astigmatism axis angle objective value. The angle shift amount is 40 °. If the objective value 30 ° of the astigmatic axis angle is displaced by the shift amount 40 °, an angle 70 ° is obtained. This angle of 70 ° is taken as the initial value of the cross cylinder test.

  The cross-cylinder test data shown in FIG. 12 is referred to in order to set an error (allowable error) allowed in the cross-cylinder test for the eye to be examined EL and ER, that is, an allowable range of measurement error in astigmatic axis angle measurement. Information. Hereinafter, this data is referred to as allowable error setting data.

  This allowable error setting data includes an allowable error in the astigmatic axis angle measurement corresponding to the objective value of the astigmatic power. More specifically, the allowable error when the objective value of astigmatism power is −0.25D is 15 °, and the allowable error when the objective value of astigmatism power is −0.50D is 10 °. The allowable error when the objective value of the astigmatism power is −0.75 to 1.25D is 5 °, and the allowable error when the objective value of the astigmatism power is −1.50 to 2.25D. Is 3 °, and the tolerance when the objective value of the astigmatism power is −2.50 to 8.00 D is 1 °.

  The permissible error for each astigmatism power defined in the permissible error setting data in FIG. 12 is set to be within an error range in which it is assumed that the astigmatism axis angle can be measured with sufficient accuracy with respect to the objective value of the astigmatism power. Has been. More specifically, the tolerance value is set so as to satisfy the following two conditions. (Condition 1) When the astigmatism axis angle is displaced from the state in which the astigmatism power of the eye to be examined EL, ER and the astigmatism axis angle are corrected by the correcting lens, the residual astigmatism occurs. It is within 25D (first predetermined range). (Condition 2) When the objective value of astigmatism and astigmatism axis angle is combined with the astigmatism and astigmatism axis angle of the correction lens, the spherical power is displaced, but the displacement of the spherical power is -0.25D (second Less than the predetermined range). The first predetermined range and the second predetermined range can be set as appropriate, but depending on the objective value of the astigmatism degree by using an allowable error that satisfies the above conditions 1 and 2. It would be possible to set an appropriate tolerance, that is, a tolerance that the measurement accuracy is not too high and not too low.

  Here, a process for setting an allowable error in the cross cylinder test using the allowable error setting data will be described. This error setting process is executed by the error setting means 102 of the control unit 80. The error setting means 102 acquires an allowable error corresponding to the astigmatism value of the astigmatism power of the eye EL and ER measured in advance from the allowable error setting data in FIG. 12, and astigmatism of the eye EL and ER. Set as the tolerance in measuring the shaft angle.

  For example, when the objective value of the astigmatism degree of the eye to be examined is −0.25D, referring to the error setting data, the angle shift amount corresponding to the objective value of the astigmatic axis angle is 15 °. 15 ° is set as an allowable error of the astigmatic axis angle measurement in the cross cylinder test. The astigmatic axis angle measurement for the eye to be examined is performed so that the final measurement value has an accuracy within this allowable error.

  Next, cross cylinder test data shown in FIGS. 13 to 15 will be described. The data shown in these figures schematically represents the process of determining the astigmatism axis angle according to the objective value of the astigmatism power. Hereinafter, this data is referred to as shaft angle determination process data (sometimes abbreviated as process data). This process data represents a process of determining the final astigmatism axis angles of the eye EL and ER while changing the astigmatism axis angle of the VCC lens 59 in what order and what value.

  The process data shown in FIG. 13A is selectively applied when the objective value of the astigmatism power is −0.255 to −0.50D. The process data shown in FIG. 13B is selectively applied when the objective value of the astigmatism power is −0.75 to −1.25D. The process data shown in FIG. 14A is selectively applied when the objective value of the astigmatism power is -1.50 to -2.25D. The process data shown in FIG. 14B is selectively applied when the objective value of the astigmatism power is −2.50 to −7.00D. The process data shown in FIG. 15 is selectively applied when the objective value of the astigmatism power is −7.25 to −8.00D. This process data is selected by the determination unit 103.

  In each axis angle determination process shown in these figures, the shift amount from the objective value of the astigmatism axis angle is shown in the upper stage, and the stage (inspection step) of the astigmatism axis measurement by the cross cylinder test is shown in the lower stage. The numerical value “0” of the upper angle shift amount indicates the objective value of the astigmatic axis angle, and the other numerical values indicate the shift amount from the objective value. On the other hand, the lower numerical values (Mal 1, Mull 2,...) Indicate the stage of astigmatic axis angle measurement by the cross cylinder test. Further, the arrow next to each numerical value in the lower row represents the input content from the lever 6h or the button 6g that is allowed when the numerical shaft angle is applied. More specifically, an arrow pointing to the right direction (left direction) represents tilting of the lever 6h to the right (left), and an upward arrow represents pressing of the button 6g.

  Further, among the numerical values in the upper stage, those surrounded by a dotted line represent the measurement results of the astigmatic axis angles of the subject's eyes EL and ER when the subject 4 inputs in accordance with the stage shown in the lower stage. That is, the plurality of stages shown in the lower part represent processes necessary for determining the measurement results of the eye to be examined EL and ER to the astigmatic axis angle surrounded by the dotted line.

  The determination means 103 of the control unit 80 compares the input content from the lever 6h and the like at each stage of astigmatism axis angle measurement with the axis angle determination process data. If the input content is the same as the arrow direction shown in the process data, the determination unit 103 determines “OK” and sends a signal to the optical head unit control unit 104. Upon receiving this signal, the optical head control means 104 controls the VCC lens driving mechanism 84L to change the VCC lens 59 to the next astigmatic axis angle. On the other hand, when the input content from the lever 6h or the like is different from the arrow direction shown in the process data, the determination unit 103 determines “error” and transmits a signal to the output control unit 105. Upon receiving the signal, the output control means 105 executes an error output process as described later.

  A specific example of the above processing will be described. In the axial angle determination process (i) in FIG. 13A, the astigmatic axis angle shifted by 40 ° from the objective value of the astigmatic axis angle is applied in the first stage (test stage 1). This shift amount 40 ° is a shift amount (see FIG. 11) set when the objective value of the astigmatism power is −0.25D. Note that the shift amount when the objective value of the astigmatism degree is −0.50D is 30 °, but in the present embodiment, the same shift amount 40 ° as in the case of −0.25D is applied.

  In the first stage, after the subject 4 confirms the appearance of the cross-cylinder test chart S in a state where an astigmatic axis angle with a shift amount of 40 ° is applied, the optical head unit 104 controls the VCC lens 59. The positive and negative shaft angles are reversed, and the appearance in that state is confirmed. If necessary, the two states are presented alternately. Then, voice navigation for inputting which state is clearly visible is output. For example, the lever 6h is tilted to the left when the appearance of the shift amount of 40 ° is clearer, and the lever 6h is tilted to the right if the appearance of the inverted state is clear, If both the appearances are equal, voice navigation prompting the user to press the button 6g is output.

  When an input operation is performed using the lever 6h or the button 6g, the determination unit 103 compares the input content with the process data shown in FIGS. Here, the arrow at the first stage is in the right direction. When the lever 6h is tilted to the right, the determination unit 103 determines “OK”, and the astigmatic axis angle of the VCC lens 59 is set to the shift amount (−20 °) of the next stage (Mal 2: second stage). Change to the next stage of inspection. On the other hand, when the lever 6h is tilted to the left or when the button 6g is pressed, the determination unit 103 determines “error” and executes an error output process.

  At this time, for example, the following processing can be applied as the error output processing. (1) Output a message such as “Please input again” and have the subject 4 input again. (2) Skip the cross-cylinder test. (3) The error determination is notified to the examination assistant by the liquid crystal monitor 64q and / or the voice output unit 86, and the operation method and the like are taught to the subject 4. (4) A conventional practice screen is displayed. The information is displayed on the liquid crystal monitor 64q (or the liquid crystal monitors 64l and 64r), and the subject 4 is made to practice.

  The liquid crystal monitor 64q and the audio output unit 86 constitute a notification unit 120 that notifies that the determination unit 103 has determined that an error has occurred. The liquid crystal monitor 64q constitutes display means for displaying a practice screen.

  Here, when it is determined that there is an error in the first stage, it is considered that the subject 4 does not understand the contents of the cross cylinder test and the operation method of the lever 6h and the like. That is, in the pair of projection images of the cross cylinder test chart S presented in the first stage, as described above, one projection image is clearly recognized and the other is visually recognized in a blurred state. . In the case of FIGS. 13A and 13I, the projected image when the shift amount is 40 ° presented first is visually recognized in a blurred state, and the projected image when the astigmatic axis is inverted is clearly visually recognized. It should be. Therefore, when it is input that the shift amount is 40 degrees (the lever 6h is tilted to the left) or both are equally clear (the button 6g is pressed), the subject No. 4 is considered that either the cross cylinder test itself is not understood or the input operation method is not understood.

  On the other hand, if the error is not determined in the first stage, that is, if it is determined OK, it can be considered that the subject 4 understands the contents of the cross cylinder test and the input operation method. . As described above, the first stage of the cross cylinder test in the present embodiment, that is, the inspection in the state where the initial value is applied, is for the purpose of understanding the inspection contents and the operation method on the practice screen that was conventionally performed before the inspection. Can be thought of as equivalent to practice.

  When the first stage is “OK”, the astigmatic axis angle of the VCC lens 59 is changed to a value shifted by −20 ° from the objective value, and the process proceeds to the second stage inspection. As can be seen from FIGS. 13A and 13I, the shift amount in the second stage is a value obtained by applying a shift amount twice the allowable error in the opposite direction (± is opposite). For example, when the objective value of the astigmatism axis angle is 30 °, the astigmatism axis angle (initial value) in the first stage is 30 ° + 40 ° = 70 °, and 30 ° −20 ° = 10 ° in the second stage. It is said.

  In the second stage, after the subject 4 confirms the appearance of the cross cylinder test chart S in a state where an astigmatic axis angle of −20 ° is applied, the positive and negative axis angles of the VCC lens 59 are reversed. Then, the visual condition in that state is confirmed, and which visual condition is clearer is input by the lever 6h or the like.

  When the input content by the lever 6h or the like in the second stage is “left”, the determination means 103 indicates “OK” because it is in the same direction as the arrow in the second stage (maru 2) in FIGS. Then, the astigmatic axis angle of the VCC lens 59 is changed to an angle corresponding to the shift amount 20 ° in the third stage (Mull 3), and the next stage inspection is performed.

  On the other hand, when the input content in the second stage is “right” or “up (equivalent)”, the determination unit 103 determines an error and shifts to an error output process. As the error output process, for example, any of the processes described above can be applied.

  The third stage is similarly performed. When shifting from the third stage to the fourth stage (the last stage), the optical head control means 104 controls the VCC lens driving mechanisms 84L and 84R to set the astigmatism power of the VCC lens 59 to the astigmatism in the previous stage. It is desirable to change to a value smaller than the frequency. For example, the astigmatic power before the last stage is ± 0.50D, and the astigmatic power at the last stage is ± 0.25D. As described above, when the astigmatic power of the VCC lens 59 in the final stage is reduced, the degree of blurring of the projected image of the cross cylinder test chart S is reduced, so that the subject 4 can visually recognize the projected image more clearly. Therefore, the ambiguity of the response in the last stage is reduced as compared with the case where the astigmatic power up to the previous stage is used as it is. That is, if the astigmatic axis angle of the eye to be examined is slightly deviated from the true value, the ± 0.50D cross cylinder lens is effective for showing a large difference between the two projected images. Since the difference between the two projection images becomes small and only two projection images with a large degree of blur are compared, it is not suitable. In the vicinity of the true value, it is better to use a cross cylinder lens of ± 0.25D, which is less blurred.

  When the determination unit 103 determines “OK” in the fourth stage, the value “0” surrounded by the upper dotted line in FIG. 13 (A) (i) is adopted as the measurement result. The measurement error of this measurement result satisfies both of the allowable errors of 15 ° and 10 ° corresponding to the objective values of −0.25 and −0.50D set by the error setting means. (See FIG. 12).

  Other determination processes shown in FIGS. 13 to 15 are executed in the same manner as in FIGS. According to the determination processes of (ii) to (iv) in FIG. 13A, the tolerances 15 ° and 10 ° corresponding to the objective values −0.25 and −0.50D of the astigmatic degree shown in FIG. Measurement results satisfying both conditions can be obtained. Moreover, according to each determination process of FIG.13 (B), the measurement result which satisfy | fills the tolerance 5 degrees corresponding to the objective value -0.75-1.25D of the astigmatism degree shown in FIG. 12 is obtained. Further, according to each determination process of FIG. 14A, a measurement result satisfying an allowable error of 3 ° corresponding to the objective value −1.50 to −2.25D of the astigmatism degree shown in FIG. 12 is obtained. Further, according to each determination process of FIG. 14B and FIG. 15, the measurement result satisfying the tolerance 1 ° corresponding to the objective value −2.50 to −8.00D of the astigmatic degree shown in FIG. can get. 14B and 15 determine the astigmatic axis angle in increments of 1 ° as will be described later, but the illustration is simplified.

  Note that the following factors are added to the determination process of FIGS. 13 (A) and 13 (iv). This determination process is a case where a value shifted by 40 ° from the objective value of the astigmatic axis angle is adopted as the measurement result. In recent years, the measurement accuracy of an objective optometry apparatus such as an autorefractometer used for objective optometry is improved, and the measurement error is about 10 °, for example. Therefore, in the determination process of FIGS. 13A and 13Iv, the measurement result of the objective optometry measurement is trusted, and if the determination is “left” at the third shift amount of 20 °, the objective value “ The appearance of “0” is confirmed once (fourth stage). When the objective value “0” is also determined to be “left”, the judgment of the subject 4 is respected, and the shift amount from the objective value of the astigmatic axis angle of the subject eyes EL and ER is 20 It is supposed to be inspected to be larger than °°.

  Here, the determination process shown in FIGS. 13 to 15 is a part of the determination process provided in the optometry apparatus 2 of the present embodiment. Assuming that the objective value of the astigmatism axis angle is A, the optometry apparatus 2 has, for example, A + 0 °, A + 10 °, A-10 ° when the objective value of the astigmatism power is −0.25 to −0.50D. , A + 20 °, A-20 °, A + 30 °, A-30 °, A + 40 °, A-40 °, A + 50 °, and A-50 ° are included as at least one determination process. ing. When the objective value of the astigmatism power is -0.75 to -1.25D, for example, A + 0 °, A + 5 °, A-5 °, A + 10 °, A-10 °, A + 15 °, A-15 ° , A + 20 [deg.], A-20 [deg.], A + 25 [deg.], And A-25 [deg.] Are included as at least one determination process. Further, in the case where the objective value of the astigmatism power is -1.50 to -2.25D, for example, A + 0 °, A + 3 °, A-3 °, A + 6 °, A-6 °, A + 9 °, A-9 ° , A + 12 [deg.], A-12 [deg.], A + 15 [deg.], And A-15 [deg.] Are included as at least one determination process. Further, when the objective value of the astigmatism power is −2.50 to −7.00 D, for example, A + 0 °, A + 1 °, A-1 °, A + 2 °, A-2 °, A + 3 °, A-3 ° A + 4 °, A-4 °, A + 5 °, A-5 °, A + 6 °, A-6 °, A + 7 °, A-7 °, A + 8 °, A-8 °, A + 9 °, A-9 ° At least one determination process is included. Further, when the objective value of the astigmatism power is −7.25 to −8.00D, for example, A + 0 °, A + 1 °, A-1 °, A + 2 °, A-2 °, A + 3 °, A-3 ° A + 4 °, A-4 °, A + 5 °, A-5 °, A + 6 °, A-6 °, A + 7 °, A-7 °, A + 8 °, A-8 °, A + 9 °, A-9 ° At least one determination process is included.

[Function and effect]
The effects achieved by the optometry apparatus 2 of the present embodiment will be described.

  First, according to the optometry apparatus 2, in the first stage of the actual cross cylinder test, the VCC lens is configured so that one of the pair of projection images of the cross cylinder test chart S is clearly visually recognized and the other is visually blurred. The initial value of 59 astigmatic axis angles is set, and the cross cylinder test is performed. Therefore, since it is possible to practice the understanding and operation of the contents of the cross cylinder test at this first stage, it is not necessary to practice the cross cylinder test before the inspection, and therefore it is not necessary to consume time. Thereby, it is possible to shorten the entire inspection time.

  In addition, since the practice and the inspection are integrally performed in this way, the test contents and the operation method once understood in the practice are not forgotten. Therefore, the cross cylinder test can be carried out smoothly and the inspection time can be shortened.

  In addition, by adopting a configuration that displays a practice screen in response to error determination, for those subjects who do not understand the test content and operation method, it can be practiced to promote understanding, For the subject who understands them, the cross cylinder test can be smoothly performed without using any practice screen, and the inspection time can be shortened.

  Further, according to the optometry apparatus 2, since an allowable axis error determination process according to the astigmatism power of the eye to be inspected is selected, the astigmatism axis angle measurement is not performed with an accuracy higher than necessary. Therefore, the cross cylinder test can be performed more quickly than before, and the inspection time can be shortened.

  In addition, since the astigmatism power of the VCC lens 59 is changed to a smaller value than the previous stage in the final stage of the astigmatic axis angle measurement, the ambiguity of the response of the subject in the last stage is reduced. The inspection time can be shortened. In addition, when a smaller astigmatism power is applied in the last stage in this way, the degree of blurring of the pair of projection images to be compared is reduced, so that the examination is completed in a state where the projection images can be seen more clearly. Therefore, the examination can be completed with a cleaner feeling than in the past. Thereby, it is possible to prevent the distrust of the eyeglass lens created based on the inspection.

  Further, when the subject's response content moves away from the objective value of the astigmatism axis angle (for example, in the case of FIGS. 13A and 13V), the appearance of the objective value is confirmed once. It is possible to correct it when the response is wrong. On the other hand, when the response content is determined to be valid, the test can be continued while respecting the response of the subject.

[Modification]
In the above embodiment, the optometry apparatus having the objective optometry measurement function for both eyes at the same time and the subjective optometry measurement function by the subject alone by the navigation of images and sounds has been described. However, the optometry apparatus according to the present invention is described below. However, the present invention is not limited to this. For example, the configuration according to the present invention is also mounted on an optometry apparatus of a type in which an optical element is selectively arranged in front of the eye to be examined (for example, an optometry unit of a subjective optometry apparatus disclosed in JP-A-2002-253503). can do.

  In the above embodiment, a variable cross cylinder lens (VCC lens) is used to form a pair of projection images of the cross cylinder test chart S. However, a cross cylinder lens of a type that reverses the front and back of the lens itself is used. May be. However, in this case, a variable cross-cylinder lens may be used because the configuration of the optical system becomes complicated, such as the need to additionally provide an optical member (such as a cylindrical lens) for changing the astigmatism power. It is considered desirable.

  In addition to the joystick lever 6h and the button 6g, any input device such as a control panel or a trackball can be used as the operation means.

  In addition to the liquid crystal monitor 64q erected on the optometry table 1, the display means for notifying the error determination and displaying the practice screen, the liquid crystal monitors 64l and 64r on the front surface of the optical heads 5l and 5r, It is possible to use a monitor of a computer device that does not, a liquid crystal display 53 in the optical head portions 5l and 5r, and the like.

  In the above embodiment, the initial value setting data, the allowable error setting data, and the shaft angle determination process data are set in the range where the objective value of the astigmatism degree is −0.25 to 8.00D. Alternatively, it may be set for objective values in other ranges. Moreover, although these data are set in 0.25D step, it is not limited to it. Further, in the initial value setting data, for example, the same angle shift amount is set for a plurality of objective values as in the case where the objective value of the astigmatism degree is -0.25D and -0.50D. A shift amount may be set for each objective value. The same applies to allowable error setting data and shaft angle determination process data.

  In the above embodiment, the astigmatism power is changed to a smaller astigmatism power in the last stage of astigmatism axis angle measurement than in the previous stage, but the change of the astigmatism power is not limited to the last stage. . That is, the astigmatism power of the cross cylinder lens after the predetermined stage of the astigmatic axis angle measurement can be changed to a value smaller than the astigmatic power before the predetermined stage. This “predetermined stage” is preferably a stage in which the stage of astigmatism axis angle measurement proceeds and approaches the true value of the astigmatism axis angle of the eye to be examined.

  The configuration described in detail above is merely an example of a configuration for implementing the optometry apparatus according to the present invention. Therefore, it goes without saying that various modifications can be made within the scope of the present invention.

It is a side view which shows an example of the outline of an external appearance structure of embodiment of the optometry apparatus which concerns on this invention. It is a perspective view which shows an example of the outline of an external appearance structure of embodiment of the optometry apparatus which concerns on this invention. It is the schematic which shows an example of a structure of the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is the schematic which shows an example of a structure of the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is the schematic which shows an example of a structure of the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is the schematic which shows an example of a structure of the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is the schematic which shows an example of a structure of the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is a perspective view which shows an example of schematic structure of the variable cross cylinder lens of the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is a block diagram which shows an example of schematic structure of the control system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is a block diagram which shows an example of schematic structure of the control system with which embodiment of the optometry apparatus which concerns on this invention is provided. It is a table which shows an example of the data for initial value setting which embodiment of the optometry apparatus which concerns on this invention has memorize | stored. It is a table which shows an example of the data for tolerance setting which the embodiment of the optometry apparatus concerning the present invention memorizes. It is a figure which shows typically an example of the shaft angle determination process data which embodiment of the optometry apparatus which concerns on this invention has memorize | stored. FIG. 13A shows an example of axial angle determination process data that is selectively applied when the objective value of the astigmatism degree of the eye to be examined is -0.25 to -0.50D. FIG. 13B illustrates an example of axial angle determination process data that is selectively applied when the objective value of the astigmatism degree of the eye to be examined is −0.75 to −1.25D. It is a figure which shows typically an example of the shaft angle determination process data which embodiment of the optometry apparatus which concerns on this invention has memorize | stored. FIG. 14A illustrates an example of axial angle determination process data that is selectively applied when the objective value of the astigmatism degree of the eye to be examined is −1.50 to −2.25D. FIG. 14B shows an example of axial angle determination process data that is selectively applied when the objective value of the astigmatism degree of the eye to be examined is −2.50 to −7.00D. Axis angle determination process data selectively applied when the objective value of the astigmatism power of the eye to be examined is −7.25 to −8.00D, which is stored in the embodiment of the optometry apparatus according to the present invention. FIG. It is the schematic which shows an example of a structure of the cross cylinder test chart shown to an eye to be examined by the measurement optical system with which embodiment of the optometry apparatus which concerns on this invention is provided.

Explanation of symbols

2 Optometry device 4 Subject 5l, 5r Optical head unit 6g Button 6h Joystick lever 53 Liquid crystal display 59 Variable cross cylinder lens 64q Liquid crystal monitor 80 Control unit 84L, 84R VCC lens driving mechanism 86 Audio output unit 100 Storage means 101 Initial value Setting means 102 Error setting means 103 Determination means 104 Optical head control means 105 Output control means S Cross cylinder test chart

Claims (6)

An optical system for projecting a target for cross cylinder testing onto the eye to be examined;
A cross-cylinder lens disposed on the optical axis of the optical system to form a pair of projected images of the target by switching the astigmatic axis angle in a state where a predetermined astigmatism power is generated;
Operation means for inputting a comparison result of the appearance of a pair of projected images of the target;
Measuring means for measuring the astigmatic axis angle of the eye to be examined based on the astigmatic axis angle of the cross cylinder lens;
Setting means for setting the amount of displacement from the objective value of the astigmatic axis angle;
When a predetermined direction is input via the operation means, the absolute value of the displacement amount is changed to a current value or less and the positive / negative of the displacement amount is reversed, and the changed displacement amount is changed to the astigmatic axis angle. Control means for changing the astigmatism axis angle of the cross cylinder lens to the added value,
The measurement means measures the astigmatism axis angle when the clarity of the pair of projection images becomes substantially equal as the astigmatism axis angle of the eye to be examined through the change of the astigmatism axis angle by the control means. To
An optometry apparatus characterized by that.   When a predetermined direction is input via the operation means for the astigmatic axis angle given as an initial value, the control means calculates an absolute value of the displacement amount given in relation to the initial value. The optometry apparatus according to claim 1, wherein the optometry apparatus decreases and reverses the positive and negative of the displacement amount.   The control means receives a predetermined direction via the operation means, and if the current value of the displacement amount and the previous value of the displacement amount are opposite in positive and negative and have the same absolute value, the absolute value of the displacement amount The optometry apparatus according to claim 1, wherein the optometry apparatus is changed by decreasing the value, and the displacement amount after the change is added to an objective value of the astigmatism axis angle. The setting means acquires a displacement amount from an objective value of an astigmatic axis angle corresponding to an objective value of the astigmatism degree of the eye to be measured in advance, and the objective value of the astigmatic axis angle is acquired. Displacement by the amount of displacement, obtain one of the pair of projection images clearly, and obtain the astigmatic axis angle of the cross cylinder lens for visually recognizing the other in a blurred state, as an initial value in astigmatic axis angle measurement Set,
The optometry apparatus according to claim 1, wherein the control unit changes an astigmatic axis angle of the cross cylinder lens starting from the initial value.   The optometry apparatus according to claim 1, wherein the storage unit stores a displacement amount from the objective value of the astigmatism axis angle in advance in association with the objective value of the astigmatism degree.   According to the correspondence stored in the storage means, the amount of displacement from the objective value of the astigmatism axis angle decreases as the absolute value of the objective value of the astigmatism degree increases. Item 4. The optometry apparatus according to Item 1.

Images