JP2010082252A - Eye refracting power measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eye refracting power measuring device for shortening an examination time in a subjective examination by recognizing the eyesight value of the eye of a subject, with a refracting power difference corrected therein, or the appropriate eyesight value of a target to be initially presented in the subjective examination. <P>SOLUTION: The eye refracting power measuring device comprises a measuring optical system provided with a projecting optical system for projecting a measurement index onto the fundus of the eye of the subject and a light receiving optical system for receiving the eye fundus reflection image reflected from the fundus of the eye by a 2D light receiving element, and in the measuring optical system, an optical element for allowing the 2D light receiving element to receive a 2D geometrical pattern image is arranged in the projecting optical system or the light receiving optical system, and the eye refracting power measuring device obtains the refracting power difference of the eye of the subject, based on the measuring optical system and the geometrical pattern images received by the 2D light receiving element. The device includes an eyesight value estimating/determining means for estimating the eyesight value of the eye of the subject with the refracting power difference corrected therein, based on the image analysis of the geometrical pattern image received by the 2D light receiving element or determining the eyesight value of the target of the eyesight examination to be initially presented in the subjective examination. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an eye refractive power measuring apparatus that measures the eye refractive power of a subject's eye.

  An eye refractive power measuring device that projects a measurement index onto the fundus of the subject's eye, detects reflected light from the fundus with a light receiving element, and measures the eye refractive power of the subject's eye based on the detection result is known. (See cited document 1). In addition, there is an optical system that presents a refractive power error (spherical refractive power error, astigmatic refractive power error) of a subject's eye, which is provided in a target-presenting optical system possessed by an eye refractive power measuring device (quoted) Reference 2). In an apparatus equipped with a correction optical system, the initial value of the correction optical system is set based on the measurement result of the objective eye refractive power measurement, and the visual acuity value target is presented in the target display optical system. Then, following the objective refractive power measurement, a subjective eye refractive power test (hereinafter, subjective test) is made possible.

In the subjective examination, a subjective eye refractive power measuring device that switches and arranges correction lenses in the left and right optometry windows is used. As a simple method, a subjective test is also performed in which a test lens is replaced with a test frame worn by a subject. In these subjective examinations, a correction lens obtained as a result of measurement by an eye refractive power measuring apparatus is generally used as an initial value.
JP 2007-89715 A JP 2006-280613 A

  By the way, in the subjective examination, if the correction lens of the measurement result obtained by the objective eye refractive power measuring device is arranged as an initial value, the eye of the subject is in a state where the refractive power error is almost corrected. Therefore, a relatively high visual acuity value target such as a visual acuity value of 0.8 or the like is set as the visual acuity test target that is initially presented. However, if the subject's eye has a large irregular astigmatism such as keratoconus, or if the subject's eye has a light scattering element in an intermediate translucent body such as opacity of the lens or vitreous opacity due to cataract Even if the refractive power error is corrected by a correction tool such as a spectacle lens, a high visual acuity index is often not readable. In this case, in the initial presentation of the visual target having a visual acuity value of 0.8, the examination time is prolonged, and the subject is burdened.

  In view of the above problems, the present invention can know the visual acuity value of the subject's eye whose refractive power error has been corrected, or the appropriate visual acuity value of the visual target initially presented during the subjective examination, and the examination during the subjective examination It is an object of the present invention to provide an ocular refractive power measuring device capable of reducing time.

  In order to solve the above problems, the present invention is characterized by having the following configuration.

(1) A measurement optical system having a projection optical system for projecting a measurement index onto the fundus of a subject's eye and a light receiving optical system for receiving a fundus reflection image reflected from the fundus with a two-dimensional light receiving element. An optical element that causes a two-dimensional light receiving element to receive a two-dimensional geometric pattern image is disposed in the projection optical system or the light receiving optical system, and the geometric pattern image received by the two-dimensional light receiving element. In the eye refractive power measurement device for obtaining the refractive power error of the subject's eye based on the subject's eye whose refractive power error has been corrected based on the image analysis of the geometric pattern image received by the two-dimensional light receiving element A visual acuity value estimating / determining means for estimating a visual acuity value of the visual acuity test target to be initially estimated during subjective examination.
(2) In the eye refractive power measurement device according to (1), the visual acuity value estimation / determination means performs image analysis on the geometric pattern image received by the two-dimensional light receiving element to measure the degree of irregular astigmatism of the subject's eye. And detecting means for detecting at least one of the turbidity of the intermediate translucent body, and estimating the visual acuity value of the subject's eye whose refractive power error has been corrected based on the detection result of the detecting means, or being aware It is means for determining a visual acuity value of a visual acuity test target initially presented at the time of inspection.
(3) In the eye refractive power measurement device according to (2), the detection means uses a geometric pattern obtained when the spherical power S, the astigmatic power C, and the astigmatic axis angle A, which are refractive power errors of the subject's eye, are obtained. On the other hand, the degree of irregular astigmatism is detected based on the geometric pattern changed in each meridian direction, or the intermediate translucent body is detected based on the distribution state of the luminance signal of the geometric pattern received by the two-dimensional light receiving element. It is characterized by detecting the degree of turbidity.
(4) The eye refractive power measurement device according to any one of (1) to (3) includes a target presentation optical system that switches and arranges a visual acuity target for a subject's eye, and an optical path of the target presentation optical system. A correction optical system having an astigmatism correction optical system and a spherical correction optical system arranged to correct a refractive power error of a subject's eye, and a measurement mode switching means for switching between an objective measurement mode and a subjective measurement mode by the correction optical system And when driving to the subjective measurement mode, the correction optical system is driven based on the refractive power error obtained by the measurement optical system, and has the visual acuity value estimated or determined by the visual acuity value estimation / determination means And a control means for presenting the inspection target on the target display optical system.
(5) The eye refractive power measurement device according to any one of (1) to (4) uses the visual acuity value obtained by the visual acuity value estimation / determination means together with the measurement result of the refractive power error obtained by the measurement optical system. Any one of output means for displaying on a screen, printing out, or outputting via communication means is provided.

  According to the present invention, it is possible to know the visual acuity value of a subject's eye whose refractive power error due to objective measurement has been corrected, or an appropriate visual acuity value of a visual target initially presented at the time of subjective examination, and an examination at the time of subjective examination Time can be shortened.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external configuration diagram of an objective eye refractive power measurement apparatus according to this embodiment. The objective eye refracting power measuring apparatus 100 moves to the base 1, the face support unit 2 attached to the base 1, the moving base 3 movably provided on the base 1, and the moving base 3. The measuring unit 4 is provided so as to accommodate an optical system described later. The measuring unit 4 is moved in the left-right direction, the up-down direction, and the front-rear direction with respect to the subject's eye E by the driving unit 6 provided on the moving table 3. The movable table 3 is moved on the base 1 in the left-right direction and the front-rear direction by operating the joystick 5. Further, the measurement unit 4 is moved in the vertical direction by the drive of the drive unit 6 by the rotation operation of the rotary knob 5a. On the top of the joystick 5, a measurement start switch 5b is provided. A display monitor 7 is provided on the movable table 3. A connector 8 for connecting a communication cable is connected to the lower side of the base 1.

  FIG. 2 is a schematic configuration diagram of an optical system and a control system of the apparatus. FIG. 3 is an explanatory diagram of the monitor display and the switch configuration of the switch unit. The measurement optical system 10 includes a projection optical system 10a that projects a spot-like measurement index on the fundus oculi Ef via the center of the pupil of the subject eye E, and fundus reflection light reflected from the fundus oculi Ef via the pupil periphery. And a light receiving optical system 10b for picking up a ring-like fundus reflection image on the image pickup device of the two-dimensional light receiving device.

  The projection optical system 10 a includes a measurement light source 11, a relay lens 12, a hall mirror 13, and a measurement objective lens 14 disposed on the optical axis L <b> 1 of the measurement optical system 10. The measurement light source 11 is arranged in a positional relationship optically conjugate with the fundus oculi Ef of the normal eye. The opening of the Hall mirror 13 is optically conjugate with the pupil of the subject's eye E.

  In the light receiving optical system 10b, the objective lens 14 and the hall mirror 13 of the projection optical system 10a are shared, and the relay lens 16 and the total reflection mirror 17 disposed on the optical axis L1 in the reflection direction of the hall mirror 13, and the total reflection mirror. 17 includes a light receiving stop 18, a collimator lens 19, a ring lens 20, and an imaging element 22 that is a two-dimensional light receiving element. The light receiving aperture 18 and the image sensor 22 are disposed in a positional relationship optically conjugate with the fundus oculi Ef. The ring lens 20 includes a lens portion in which a cylindrical lens is formed in a ring shape on a transparent flat plate shape, and a light shielding portion where light is shielded except for the ring-shaped lens portion. The positional relationship is conjugate to the above. An output from the image sensor 22 is input to the control unit 70. In addition, the measurement light source 11 and the relay lens 12 of the projection optical system 10a, and the collimator lens 19, the ring lens 20, and the imaging element 22 of the light receiving optical system 10b are integrally moved in the optical axis direction by the moving mechanism 23. .

  In this apparatus, the ring lens 20 is used to cause the image sensor 22 to receive a ring image that is a measurement index of a two-dimensional geometric pattern. However, as a measurement index of a two-dimensional geometric pattern, An optical element (for example, one described in Japanese Patent Application Laid-Open No. 2001-204690) having a dot distributed in a ring shape, a dot distributed in a lattice shape, or a micro lens is disposed in the measurement optical system 10. May be. An optical element that causes the image sensor 22 to receive these two-dimensional geometric patterns is not arranged in the light receiving optical system 10b, but as in the optical system described in Japanese Patent Laid-Open No. 10-14876. The projection optical system 10a may be disposed.

  Between the objective lens 14 and the subject eye E, the target luminous flux from the target presentation optical system 30 is guided to the subject eye E, and the reflected light from the anterior eye part of the subject eye E is observed. A dichroic mirror 29 leading to the optical system 50 is disposed. The dichroic mirror 29 transmits the wavelength of the measurement light beam used in the measurement optical system 10.

  The observation optical system 50 includes an imaging lens 51 and a two-dimensional imaging device 52 that are arranged on the optical axis in the reflection direction of the half mirror 38. An output from the image sensor 52 is input to the control unit 70. As a result, the anterior segment image of the subject's eye E is captured by the two-dimensional image sensor 52 and displayed on the monitor 7.

  The optotype presenting optical system 30 shares the objective lens 39 of the observation optical system 50, and includes a light source 31 such as an LED disposed on the optical axis L <b> 2 coaxial with the optical axis L <b> 1 by the dichroic mirror 29, and a target plate 32. , Relay lens 33 and reflecting mirror 36. The optotype presenting optical system 30 is shared with the refractive power correcting optical system for correcting the refractive power of the subject's eye, and the astigmatism correcting optical system 34 is disposed between the reflecting mirror 36 and the relay lens 33. ing.

  On the optotype plate 32, a plurality of optotypes 32a including a fixation target for performing cloud fog on the subject's eye E at the time of objective measurement and an optotype for visual acuity test used at the time of subjective measurement are arranged on a concentric circle. Has been. As the visual acuity test target, visual targets for each visual acuity value (visual acuity values 0.1, 0.3,..., 1.5) are prepared. The optotype plate 32 is rotated by a motor 37, and the optotype 32a is switched and disposed on the optical axis L2 of the optotype presenting optical system 30. The target luminous flux of the target 32a illuminated by the light source 31 travels toward the subject's eye E via an optical member from the relay lens 33 to the dichroic mirror 29.

  The light source 31 and the target plate 32 (target 32a) are integrally moved in the direction of the optical axis L2 by a drive mechanism 38 including a motor and a slide mechanism. By moving the light source 31 and the target 32a, cloud is applied to the subject's eye E during objective measurement, and the target presentation position (presentation distance) with respect to the subject's eye is optically changed during subjective measurement. As a result, the spherical refractive power of the subject's eye is corrected. That is, a correction optical system having a spherical power is configured by the movement of the objective lens 39, the relay lens 33, the light source 31, and the target 32a.

  The astigmatism correction optical system 34 includes two positive cylindrical lenses 34a and 34b having the same focal length. The cylindrical lenses 34a and 34b are independently rotated about the optical axis L2 by driving the rotation mechanisms 35a and 35b, respectively. The correction optical system may have a configuration in which the correction lens is taken in and out of the optical path of the optotype presenting optical system. The correction optical system having a spherical power may be configured by adding a relay lens that can move in the optical axis direction to the visual target presenting optical system.

  The control unit 70 is connected to the image sensor 22 and performs a refractive power calculation process based on the output of the image sensor 22. The control unit 70 includes an image sensor 52, a moving mechanism 23, a driving mechanism 38, a motor 37, a light source 31, rotating mechanisms 35a and 35b, a display monitor 7, and a switch unit 80 used for various settings (an objective measurement and a subjective measurement). A switch 80a for changing the visual acuity, switches 80b and 80c for changing the visual acuity value of the presented target, a switch 80b for printing out the measurement result, and switches 80e and 80f for changing the spherical power of the correction lens), measurement The start switch 5b, the image memory 75, the drive unit 6, the printer 90, and the like are connected.

  Next, the measurement operation of the apparatus having the above configuration will be described. When the device is activated, the objective power measurement mode is set. The visual target 32a of the visual target presenting optical system 30 has a fixation target for objective measurement for performing cloud fog on the subject eye E set in the optical path. The examiner fixes the subject's face to the face support unit 2, and a fixation target arranged in the measurement unit 4 via the measurement window 4 a (see FIG. 1) of the measurement unit 4 is applied to the subject's eyes. Let me fix it.

  When measuring objective refractive power, the anterior segment of the subject's eye E is imaged by the imaging element 52 of the observation optical system 50, and an anterior segment image is displayed on the monitor 7. The examiner observes the anterior segment image on the monitor, the alignment target image (not shown), and the reticle, and moves the measurement unit 4 and the movable table 3 by operating the joystick 5 or the like, thereby The optical system is aligned with a predetermined positional relationship. When the measurement start signal is input from the measurement start switch 5b after the alignment is completed, the refractive power is measured.

  The measurement light emitted from the light source 11 is projected onto the fundus oculi Ef via the relay lens 12 to the dichroic mirror 29, and forms a spot-like point light source image on the fundus oculi Ef. The light of the point light source image formed on the fundus oculi Ef is reflected and scattered, exits the subject's eye E, is condensed by the objective lens 14, and is received through the hole mirror 13 through the total reflection mirror 17. The light is condensed again on the aperture 18, is made into a substantially parallel light beam (in the case of a normal eye) by the collimator lens 19, is taken out as a ring-shaped light beam by the ring lens 20, and is received by the image sensor 22 as a ring image R.

  In the measurement of objective eye refractive power, preliminary measurement of the eye refractive power is first performed, and the eye to be examined is moved by moving the light source 31 and the fixation target plate 32 in the direction of the optical axis L2 based on the result of the preliminary measurement. E is clouded. Thereafter, the main measurement of the eye refractive power is performed on the eye to be inspected with fog.

  FIG. 4A is an example of a ring image R imaged on the image sensor 22 at the time of measurement. An output signal from the image sensor 22 is stored in the image memory 75 as image data (measurement image). After that, the control unit 70 analyzes the ring image stored in the image memory 75 and specifies the position of the ring image in each meridian direction. The control unit 70 cuts the luminance signal distribution of the ring image at a predetermined threshold (for example, a threshold of 75% with respect to the luminance peak), and at the cutting position, the midpoint of the luminance signal distribution and the luminance signal centroid By obtaining the position and the like, each meridian position for each degree of the ring image is specified. Next, the control unit 70 approximates the ellipse using the least square method or the like based on the specified ring image position.

  FIG. 4B is an example of the approximated elliptical shape Ea. The control unit 70 obtains the refractive power error in each meridian direction from the elliptical shape Ea, and based on this, the refractive power of the spherical power S, astigmatism power C, and astigmatic axis angle A of the subject eye (refractive power error for normal vision). Is calculated. When there is a refractive power error of only the spherical power S, the elliptical shape Ea becomes a perfect circle, and the distance r from the center O of the circle to the circular shape changes. A spherical power S is obtained based on the change in the distance r. Further, when there is a refractive power error of the astigmatic power C, the astigmatic power C is obtained from the difference in the distance r between the weak main meridian and the strong main meridian of the elliptical shape Ea, and the astigmatic axis angle depends on the direction of the weak main meridian or the strong main meridian. A is required. The measurement result is displayed on the monitor 7. Usually, the measurement value of the objective eye refractive power measurement device is calculated as a frequency when the eye is corrected with a toric eyeglass lens or contact lens.

  Further, the control unit 70 uses the two-dimensional geometric pattern ring image stored in the image memory 75 to determine the visual acuity value (hereinafter referred to as the visual acuity value) when the subject's eye corrects the refractive error of the objective measurement result. The corrected visual acuity value) is estimated or the visual acuity value of the visual acuity test target initially presented at the time of subjective examination is determined. Factors that cause the corrected visual acuity value to fluctuate mainly include the influence of irregular astigmatism and the influence of the turbid state of the intermediate translucent body (the state of the light scattering element).

  A method for estimating the corrected visual acuity value based on the detection result of the degree of irregular astigmatism will be described. The ring image R shown in FIG. 4A is an example of a state in which there is no irregular astigmatism such as a keratoconus and turbidity of an intermediate light transmitting body (a crystalline lens or a vitreous body). In this case, the width of the ring image R is relatively narrow and is detected as a ring image with high brightness. In contrast, FIG. 5A is an example of a ring image R of an eye having irregular astigmatism such as a keratoconus. FIG. 5B is an example of the ring image position Ra specified from the ring image R and an elliptical shape Ea approximated to the ring image position Ra. The ring image position Ra has a large deviation from the approximated elliptical shape Ea, and irregular distortion portions appear.

  The control unit 70 obtains a deviation amount Δpθ between the refractive power pRθ (diopter) corresponding to the ring image position Ra and the refractive power pEθ (diopter) corresponding to the elliptical shape Ea in each meridian direction θ, and then the deviation amount. A sum Tp (diopter) of absolute values of Δpθ is obtained. The shift amount Δpθ is obtained, for example, every 1 degree. In calculating the total sum Tp (diopter), after obtaining the deviation amount Δr of the distance between the ring image position Ra and the elliptical shape Ea in each meridian direction, the total amount Rr of the deviation amount is obtained, and then the ring image From the relationship with the refractive power corresponding to the distance of the position Ra, the total deviation amount Rr may be converted into refractive power.

  The control unit 70 estimates a corrected visual acuity value based on the total sum Tp. A larger total sum Tp indicates a greater degree of irregular astigmatism. Therefore, the corrected visual acuity value decreases as the total sum Tp increases. FIG. 8 is an example of estimating a corrected visual acuity value corresponding to irregular astigmatism. The corrected visual acuity value is estimated in, for example, five levels from level 1 to level 5 according to the total Tp. Assume that the degree of irregular astigmatism increases in the order of levels 1, 2, 3, 4 and 5, and the corrected visual acuity value also decreases. Each level has a total Tp value of less than 2.00D, 2.00D or more and less than 5.00D, 5.00 or more and less than 8.00D, 8.00D or more and less than 11.00D, and 11. It is classified as 00D or more and estimated as visual acuity values of 0.9 or more, 0.8, 0.7, 0.5, or 0.4 or less, respectively. This corrected visual acuity value is set based on experience.

  Next, a method for estimating the corrected visual acuity value based on the detection result of the turbidity of the intermediate translucent body will be described. FIG. 6 is an example of an eye ring image in which the intermediate translucent body is turbid. In this case, since the measurement light is scattered by the cloudy part of the eye, the width of the ring image is thicker than that in FIG. FIG. 7 is a diagram showing the distribution of the luminance signal I in a cross section in a certain meridian direction with respect to the ring image of FIG. The control unit 70 cuts the distribution of the luminance signal I at a predetermined threshold S (for example, a threshold of 75% with respect to the luminance peak), and obtains the width W from the cutting positions ra and rb from the center O. Further, the width W is converted into a refractive power pW (diopter) based on the refractive power at the cutting positions ra and rb from the center O (or an intermediate point between them). Then, after obtaining the refractive power pW in each meridian direction (for example, every 1 degree), the control unit 70 obtains the average refractive power AVpW (diopter).

  Next, the control unit 70 estimates a corrected visual acuity value based on the average refractive power AVpW. It shows that the turbidity degree of an intermediate | middle translucent body is so large that the value of refractive power AVpW is large. Accordingly, the corrected visual acuity value decreases as the refractive power AVpW increases. FIG. 9 is an example of estimating the corrected visual acuity value according to the turbid state of the intermediate translucent body. The corrected visual acuity value is estimated in five levels from level 1 to level 5 according to the refractive power AVpW, as in the case of irregular astigmatism in FIG. It is assumed that the opacity of the intermediate translucent body increases in the order of levels 1, 2, 3, 4 and 5, and the corrected visual acuity value also decreases. For each level, the refractive power AVpW is less than 0.10D, 0.10D or more, less than 0.20D, 0.20D or more, less than 0.30D, 0.30D or more, less than 0.40D, 0.40D They are classified as described above, and are estimated as visual acuity values of 0.9 or more, 0.8, 0.7, 0.5, and 0.4 or less, respectively. This corrected visual acuity value is set based on experience.

  As described above, the control unit 70 estimates the corrected visual acuity values based on the detection results of the degree of irregular astigmatism and the opacity of the intermediate translucent body. Is the estimated corrected visual acuity value. The estimated corrected visual acuity value is displayed on the screen of the monitor 7 together with the measurement results S, C, and A of the objective measurement as “VA * 0.5”. When the switch 80b is pressed, the corrected visual acuity value estimated together with the measurement results S, C, and A of the objective measurement is printed out from the printer 90. In selecting the visual acuity test target to be initially presented at the subjective examination, the corrected visual acuity value does not necessarily have to be estimated, and the visual acuity value of the initial presentation is determined according to levels 1 to 5 in FIGS. The structure by which a mark is determined may be sufficient.

  When the objective measurement is completed and the switch 80a for switching to the subjective examination measurement screen is selected, the control unit 70 determines the refractive power (spherical power S, astigmatism power C, astigmatism) of the subject's eye obtained by the objective measurement. The correction optical system is driven based on the axial angle A) to correct the refractive power error of the subject's eye. That is, the light source 31 and the target plate 32 are moved in the direction of the optical axis L2 based on the spherical power S so that the refractive power error of the spherical refractive power S is corrected. Further, the astigmatism correction optical system 34 is driven based on the astigmatism power C and the astigmatism axis angle A, and a correction state in which the refractive power error of astigmatism is corrected is obtained.

  Moreover, the control part 70 switches the visual acuity value visual target of the visual target board 32 based on the correction visual acuity value estimated at the time of objective measurement. For example, when the subject's eyes have irregular astigmatism or the intermediate translucent body is turbid and the degree thereof is determined to be level 4, the corrected visual acuity value is 0, as shown in FIG. 5 is estimated. The control unit 70 rotates the target plate 32 by driving the motor 37, and arranges the visual acuity test target having a visual acuity value of 0.5 on the optical axis L2 as an initial presentation target for the subjective examination. Even if the level of the irregular astigmatism or the opacity state of the intermediate translucent body is determined to be level 1, even if the initial presentation target is not a visual acuity value of 0.9, it is conventional for visual acuity confirmation. Similarly, the visual acuity value may be set to 0.8.

  As described above, when the initial presentation target is presented to the subject's eye, the examiner performs a visual acuity test on the subject. The visual target is switched by operating the switches 80b and 80c according to the response of the subject. When the test subject's answer is correct, the switch 80b is selected to switch to a visual target having a higher visual acuity value. On the other hand, if the subject's answer is an incorrect answer, the switch 80c is selected to switch to a target with a visual acuity value that is one step lower. By repeating the above procedure, the maximum visual acuity that can be read by the subject is examined. At the time of this highest visual acuity test, the visual acuity test target that is initially presented is set based on the corrected visual acuity value estimated at the time of objective measurement, so the visual acuity test starts from the visual acuity value close to the highest visual acuity value of each subject Is done. For this reason, unnecessary repetition of the visual acuity test is reduced, and the examination time is shortened.

  When the maximum visual acuity value based on the correction power of the objective measurement result is obtained, the examiner adjusts the spherical power (the weakest power) more positive than the subject to obtain the maximum visual acuity value. The spherical power S is changed by the above operation. When the switch 80e or 80f is selected, the light source 31 and the target plate 32 are moved in the direction of the optical axis L2, and the spherical power is changed. As a result, the weakest spherical power S that provides the highest visual acuity is determined, and a reference value for prescribing the power of a spectacle lens or a contact lens is obtained.

  Regarding the above estimated visual acuity value estimation result, whether the corrected visual acuity value is estimated based on irregular astigmatism or due to the opacity of the intermediate translucent body is displayed at the same time. It is convenient if is displayed. Thus, the examiner can explain the condition of the subject's eye that is the cause when the corrected visual acuity value of the subject is low. Also, in medical institutions such as ophthalmologists, evaluation of the condition of the subject's eye can be obtained from the objective measurement result of the eye refractive power measurement device that is first performed. it can.

  In the above-described case, the eye refractive power measurement device with the subjective refractive power measurement function is used to perform both objective measurement and subjective measurement of the subject's eye. The present invention can also be applied to a case where the refractive power measurement device is used and the subjective examination is performed by sharing data with other subjective examination devices.

  FIG. 10 shows an example of an optometry system in which objective measurement is performed by the objective eye refractive power measurement apparatus 100 and subjective examination is performed by the subjective eye refractive power measurement apparatus. The optometry system includes a subjective eye refractive power measurement unit 500 in which various optical elements (correction lenses and auxiliary lenses) are switched and arranged in the left and right inspection windows 501 and a visual display in which an inspection target is displayed on a display 531 such as a liquid crystal display. The sign presenting device 530, an operation unit 520 for inputting a command signal for operating the measurement unit 500 and the optotype presenting device 530, and a relay unit 510 for relaying transmission / reception of the command signal between the units. The operation unit 520 is provided with a connector 521 for connecting the communication cable 800, and the operation unit 520 and the eye refractive power measuring apparatus 100 are connected via the communication cable 800.

  When the objective measurement in the eye refractive power measuring apparatus 100 is completed and the print switch 80d is pressed by the examiner, the objective measurement result and the estimated corrected visual acuity value data are output and operated via the communication cable 800. To unit 520. The objective measurement data (S, C, A) is sent to the measurement unit 500, and the initial value of the correction optical system is set based on the objective measurement data. The corrected visual acuity value data is sent to the visual target presenting device 530, and the visual acuity visual target for initial presentation is set based on the data.

  As described above, the corrected visual acuity value obtained by the objective eye refracting power measuring apparatus 100 is output, so that it is used in the subjective optometry system. At this time, if the guess of the corrected visual acuity value is low such as a visual acuity value of 0.3, 0.5, etc., compared to the case where the visual acuity test is started from a conventional visual acuity value of 1.0, 0.8, etc. The time required for visual acuity testing at the subjective examination stage is shortened.

  In the subjective examination using the test frame and the test lens instead of the subjective eye refractive power measurement unit 500, the examiner uses the corrected visual acuity value output from the printer 90 of the eye refractive power measuring apparatus 100 as a result. Based on this, it is possible to determine the initial value of the visual acuity test target to be presented to the visual target presentation device 530. In this case as well, the visual acuity test time at the subjective examination stage is shortened as described above.

It is an external appearance block diagram of an objective type eye refractive power measuring apparatus. It is a schematic block diagram of the optical system and control system of an apparatus. It is explanatory drawing of a monitor display and the switch structure of a switch part. It is an example of the ring image imaged with the image pick-up element, and the approximate ellipse shape. It is an example of a ring image of an eye with irregular astigmatism and an approximate elliptic shape. It is an example of the ring image of the eye which has turbidity in an intermediate translucent body. It is the figure which showed the luminance signal distribution of the cross section of the meridian direction with the ring image of FIG. It is an estimation example of the corrected visual acuity value according to irregular astigmatism. It is an estimation example of the corrected visual acuity value according to the turbid state of the intermediate translucent body. It is an example of an optometry system in a case where objective measurement is performed by an objective eye refractive power measurement device and a subjective examination is performed by the subjective eye refractive power measurement device.

Explanation of symbols

7 Display Monitor 10 Measurement Optical System 10a Projection Optical System 10b Light Receiving Optical System 22 Image Sensor 30 Target Display Optical System 70 Control Unit 80 Switch Unit 100 Objective Eye Refractive Power Measurement Device 531 Display 800 Communication Cable

Claims (5)

A measurement optical system having a projection optical system for projecting a measurement index onto the fundus of a subject's eye and a light receiving optical system for receiving a fundus reflection image reflected from the fundus with a two-dimensional light receiving element, the two-dimensional light receiving element An optical element that receives a two-dimensional geometric pattern image on the projection optical system or the light receiving optical system and a geometric pattern image received on the two-dimensional light receiving element. In an eye refractive power measuring device that obtains a refractive power error of an examiner's eye,
A visual acuity test target that estimates a visual acuity value of a subject's eye whose refractive power error has been corrected based on an image analysis of a geometric pattern image received by the two-dimensional light receiving element, or initially presented during a subjective examination An eye refractive power measuring apparatus comprising eyesight value estimation / determination means for determining a visual acuity value of the eyesight. In the eye refractive power measuring device according to claim 1,
The visual acuity value estimation / determination means detects at least one of the degree of irregular astigmatism of the subject's eye and the opacity of the intermediate translucent body by performing image analysis on the geometric pattern image received by the two-dimensional light receiving element. Having a detection means, based on the detection result of the detection means, the visual acuity value of the eye of the subject whose refractive power error has been corrected is estimated, or the visual acuity value of the visual acuity test target initially presented at the subjective examination is determined An eye refractive power measuring apparatus characterized by comprising: In the eye refractive power measuring device according to claim 2,
The detecting means is based on a geometric pattern that changes in each meridian direction with respect to the geometric pattern when the spherical power S, the astigmatic power C, and the astigmatic axis angle A, which are refractive power errors of the subject's eye, are obtained. Detecting the degree of irregular astigmatism, or detecting the opacity of the intermediate translucent body based on the distribution state of the luminance signal of the geometric pattern received by the two-dimensional light receiving element. apparatus. The eye refractive power measuring device according to any one of claims 1 to 3,
An optotype presenting optical system that switches and arranges a visual acuity target on the subject's eye;
A correction optical system disposed in the optical path of the target presentation optical system and having an astigmatism correction optical system and a spherical correction optical system for correcting a refractive power error of the subject's eye;
Measurement mode switching means for switching between an objective measurement mode and a subjective measurement mode by the correction optical system;
When switched to the subjective measurement mode, the correction optical system is driven based on the refractive power error obtained by the measurement optical system, and the visual inspection value has the visual acuity value estimated or determined by the visual acuity value estimation / determination means. Control means for presenting a target on the visual target presenting optical system;
An eye refractive power measuring device comprising: Whether the eye refractive power measurement device according to any one of claims 1 to 4 displays the visual acuity value obtained by the visual acuity value estimation / determination means together with the measurement result of the refractive power error obtained by the measurement optical system on the screen. An eye refractive power measuring device comprising any output means for printing out or outputting via a communication means.