JP5342211B2 - Eye refractive power measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily recognize whether an additional degree is necessary or not for a subject's eye when the visual acuity is measured for myopia, and to measure the visual acuity for myopia with the addition of the additional degree in a short period of time. <P>SOLUTION: The eye refractive power measuring apparatus includes a refractive power measuring means for measuring the refractive power of the subject's eye by projecting a measuring target on the ocular fundus and receiving the light flux reflected from the ocular fundus by a light receiving element; and a visual target presenting optical system for changing the visual target to be presented to the subject's eye from the hyperopic distance to the myopic distance. The eye refractive power measuring apparatus also includes: an input means for inputting a transfer signal to the measurement of the visual acuity for myopia; a control means for switching the visual target of the visual target presenting optical system to the myopic distance in the measurement of the visual acuity for myopia; a conducting means for measuring the refractive power by the refractive power measuring means when the visual acuity is measured for myopia; and a determining means for finding the refractive power necessary for the subject's eye to see the visual target in the myopic distance, comparing the found refractive power with the refractive power for myopia obtained by the measuring means, determining whether the additional degree is necessary for the subject's eye in the measurement of the visual acuity for myopia, and announcing the result of the determination. <P>COPYRIGHT: (C)2010,JPO&amp;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, receives a reflected light beam from the fundus on a light receiving element, and objectively measures the refractive power of the subject's eye based on the output of the light receiving element. Is known (see, for example, Patent Document 1). This apparatus has a visual target presenting optical system in which the presenting distance of a fixation target presented to the subject's eye is variable, and the refractive power at a distance is measured in a clouded state. In addition, there is an apparatus in which a subjective refractive power measurement function having a correction optical system that corrects astigmatism and spherical refractive power is added to a target presentation optical system (see, for example, Patent Documents 2 and 3). In this apparatus, the visual acuity of the visual target presenting optical system is presented at a predetermined near distance, and the near visual acuity measurement in a state in which the addition is added to the corrected state for distance by driving control of the correcting optical system ( Near vision test) is also possible.
JP 2004-129711 A JP 59-80227 A JP 2006-280613 A

  However, since the degree of accommodation of the subject's eye is unknown, the examiner can respond to the subject's response as to whether or not the subject's eye needs additional power when measuring near vision. I had to wait and judge. Even when near vision measurement with addition is required, conventionally, the addition is started from a certain value, or the age of the subject is estimated and the initial value of the addition according to the age is empirically determined. Was set to. In addition, the examiner adjusts the addition while confirming the appearance of the subject, but when the addition required by the examinee's eye is far from the initial value, an appropriate addition was added. It takes time to measure near vision and increases the burden on the subject and the examiner. In addition, it takes time to determine an appropriate addition in the confirmation of the appearance based on the presence or absence of the addition.

  In view of the above-described problems of the prior art, the present invention can easily know whether or not the subject's eye needs addition at the time of measuring near vision, and near vision with added addition It is an object of the present invention to provide an eye refractive power measuring device capable of performing measurement in a short time.

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

(1) An eye refractive power measuring means for projecting a measurement index onto the fundus of the subject and receiving a reflected light beam from the fundus with a light receiving element to obtain the refractive power of the subject's eye, and presenting it to the subject's eye An eye for providing a distance refractive power by presenting the target at a distance for which a cloud is fogged by the target presenting optical system. In the refractive power measurement device,
And the near-distance use refractive power measurement means for executing the refractive power measured by Oite the eye refractive power measuring means in a state where target is presented to the predetermined near distance,
Based on the distance refractive power of the subject's eye and the near distance, the subject's eye calculates the refractive power necessary for viewing the target at the near distance, and the calculated refractive power and the near distance Comparing the refractive power for near use obtained by the refractive power measurement execution means, and determining whether or not the eye of the subject needs addition, and notifying the result ,
The determining means is the eye is characterized that you determined to require diopter when the frequency of the comparison result exceeds a predetermined power adjustment lug of the eye.
(2) a correction optical system that corrects astigmatism refractive power and spherical refractive power of a subject's eye, and a target presentation means for presenting a target at a near distance of the subject's eye; An eye refractive power measuring device for measuring eye refractive power of an eye,
An eye refractive power measuring means for projecting a measurement index onto the fundus of the subject and receiving a reflected light beam from the fundus with a light receiving element to obtain the refractive power of the subject's eye, and a target to be presented to the subject's eye An optotype eye refractive power measurement device comprising: an optotype presenting optical system that varies from a distance for a distance to a distance for a near distance, wherein the target is presented at the distance for distance or near distance The distance refractive power and the near distance obtained by the objective eye refractive power measuring device for measuring the distance refractive power and the near refractive power by the eye refractive power measuring means, respectively. The subject eye compares the refractive power necessary for viewing the near-distance target and the near refractive power, and determines whether or not the subject eye requires addition power. Judgment means for informing the result, and
The determination means determines that the eye of the subject needs addition when the frequency of the comparison result exceeds a predetermined frequency of the eye adjustment lag.

  According to the present invention, it is possible to easily know whether or not the subject's eye needs an addition during near vision measurement, and to perform near vision measurement with addition in a short time. Can do.

  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 (X direction), the up-down direction (Y direction), and the front-rear direction (Z direction) with respect to the subject 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. A measurement start switch 5 b is provided on the top of the joystick 5. A display monitor 7 is provided on the movable table 3.

  FIG. 2 is a schematic configuration diagram of an optical system and a control system of the apparatus. The eye refractive power measurement optical system 10 includes a projection optical system 10a that projects a spot-like measurement index on the fundus oculi Ef through the center of the pupil of the subject eye E, and fundus reflection light reflected from the fundus oculi Ef. And a light receiving optical system 10b that picks up a ring-shaped fundus reflection image on the imaging element of the two-dimensional light receiving element.

  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 diaphragm 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, and a light shielding portion where light is shielded except for the ring-shaped lens portion. The ring lens 20 is optically conjugate with the pupil of the eye E through an optical system from the objective lens 14 to the collimator lens 19. An output from the image sensor 22 is input to the control unit 70. Further, the measurement light source 11 of the projection optical system 10a, the collimator lens 19, the ring lens 20, and the image sensor 22 of the light receiving optical system 10b are integrally moved by the moving mechanism 23 in the optical axis direction. As the eye refractive power measuring optical system 10, a well-known one can be used.

  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.

  An alignment index projection optical system 40 is disposed in front of the anterior segment of the subject's eye E. The alignment index projection optical system 40 includes a ring index projection optical system 41 that projects a ring index on the cornea of the subject's eye E, an index projection optical system 42 that projects an infinite index of two bright spots on the cornea Ec, Is provided. The index projection optical system 42 is arranged symmetrically with respect to the observation optical axis. The ring index projection optical system 41 is also used as anterior segment illumination that illuminates the anterior segment of the subject's eye E.

  The observation optical system 50 includes an imaging lens 51 and a two-dimensional imaging element 52 arranged on the optical axis in the reflection direction of the half mirror 53. 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 observation optical system 50 also serves as an optical system that detects an alignment index image formed on the cornea of the eye E by the alignment index projection optical system 40, and is in an alignment state based on the position detection of the alignment index image by the control unit 70. The suitability is determined.

  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.

  The target plate 32 has a plurality of targets 32a including a fixation target for performing clouding on the subject's eye E during objective refractive power measurement and a visual test for visual acuity used during subjective refractive power measurement. They are arranged on concentric circles. 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, the target display position (presentation distance) is optically changed from the distance to the near distance. As a result, cloud is applied to the subject eye E during objective refractive power measurement, and the spherical refractive power of the subject's eye is corrected during subjective refractive power measurement. 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 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 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 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, a switch unit 80 used for various settings, a measurement start switch 5b, and an image. The memory 75, the drive unit 6, the printer 90, and the like are connected.

  FIG. 3 is an explanatory diagram of the switch configuration of the switch unit 80 and the display on the monitor 7. The screen of the monitor 7 in FIG. 3 is an example of the subjective visual acuity measurement screen 200. In the switch unit 80, eight switches 80a to 80h are arranged. The function of each switch signal is switched in accordance with the screen of the monitor 7 that is switched by selecting the measurement mode.

  Next, the measurement operation of the apparatus having the above configuration will be described. When the device is activated, it is set to the objective power measurement mode for distance use. In this case, as the visual target 32a of the visual target presenting optical system 30, a fixation target (for example, a landscape visual target) for applying cloud fog is 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. In addition, the ring index image projected by the ring projection optical system 41 and the index image at infinity projected by the index projection optical system 42 are captured by the image sensor 52. These alignment index images are also displayed on the monitor 7. The examiner observes the anterior segment image, alignment target image, and reticle on the monitor 7, moves the measurement unit 4 and the moving table 3 by operating the joystick 5, etc. Are aligned in 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.

  When the automatic alignment mode is set by a switch (not shown), the control unit 70 detects the alignment state based on the alignment index image captured by the image sensor 52. The alignment state in the vertical and horizontal directions is detected by the positional relationship between the center position of the ring index image by the ring projection optical system 41 and the optical axis. The alignment state in the working distance direction is detected by utilizing the characteristic that the infinity index by the index projection optical system 42 does not change even if the working distance changes, and the image interval in the predetermined meridian direction of the ring index changes. (See JP-A-6-46999). Based on the detection results of these alignment index images, the drive unit 6 is driven, and the measurement unit 4 is moved so that the alignment state is appropriate. When the alignment is completed, a trigger for a measurement start signal is automatically issued by the control unit 70, and the distance power measurement is performed.

  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 by the fundus occupying the subject eye E, and the optical system up to the objective lens 14, the hall mirror 13, the relay lens 16 and the total reflection mirror 17. Then, the light is condensed again on the aperture of the light receiving diaphragm 18 and is made into a substantially parallel light beam (in the case of a normal eye) by the collimator lens 19. It is taken out as a ring-shaped light beam by the ring lens 20 and received by the image sensor 22 as a ring image.

  In the measurement of the distance objective eye refractive power, first, preliminary measurement of eye refractive power is performed, and the light source 31 and the fixation target plate 32 are moved in the direction of the optical axis L2 based on the result of the preliminary measurement. The cloud E is applied to the eye E. Thereafter, the main measurement of the eye refractive power is performed on the eye to be inspected with fog. In this measurement, a ring image by the ring lens 20 is picked up by the image pickup device 22, and an output signal from the image pickup device 22 is stored in the image memory 75 as image data (measurement image). Thereafter, the control unit 70 performs image analysis on the ring image stored in the image memory 75 to obtain the value of refractive power in each meridian direction. The control unit 70 obtains objective values of S (spherical power), C (astigmatic power), and A (astigmatic axis angle) of the subject's eye during distance use by performing a predetermined process on the refractive power. . The objective value obtained at the time of distance use is stored in the memory 75.

  The eye refractive power measurement optical system 10 is not limited to the configuration using the ring-shaped index image as described above, and projects the measurement index on the fundus, receives the reflected light beam from the fundus with the light receiving element, and at least 3 Any optical system that obtains the refractive power in the meridian direction can be used, and a known one can be used.

  When the objective power measurement for distance use is completed and the switch 80a is pressed, the monitor 7 switches to the subjective distance vision measurement (objective power measurement) mode, and the screen of the monitor 7 is the screen of the objective power measurement mode. (Not shown) is switched to the subjective distance vision measurement screen 200 shown in FIG. The control unit 70 drives the correction optical system based on the refractive power (spherical power S, astigmatism power C, astigmatism shaft angle A) of the subject's eye obtained by measuring the objective refractive power for distance use. Correct the refractive error of the human 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 in the distance objective refractive power measurement, 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. Further, the control unit 70 rotates the target plate 32 by controlling the rotation of the motor 37, and arranges a predetermined visual acuity value visual target 32a on the optical axis L2 (for example, a visual target having a visual acuity value 0.8).

  As described above, when the initial presentation target is presented to the subject's eye, the examiner measures the distance vision of the subject. When the switches 80b and 80c corresponding to the UP and DOWN displays 202a and 202b of the visual acuity value are pressed, the visual acuity value target to be presented is switched. If the examinee's answer is correct, the examiner selects the switch 80b 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. The control unit 70 rotates the visual target plate 32 based on a signal input for changing the visual acuity value by the switch 80b or 80c, and switches the visual acuity value visual target 32a on the optical axis of the visual target presenting optical system. The examiner obtains the maximum visual acuity that can be read by the subject by repeating the above procedure.

  When the maximum vision value for distance using the correction power of the objective refractive power measurement result is obtained, the examiner adjusts the spherical power (the weakest power) from the most plus that allows the subject to obtain the highest vision value. The spherical power S is changed by operating the switches 80f and 80g corresponding to the UP / DOWN displays 204a and 204b for changing the spherical power in FIG. When the switch 80f or the switch 80e 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 at which the highest visual acuity is obtained is determined, and a reference value for prescribing the distance correction power such as a spectacle lens or a contact lens is obtained.

  Next, the examiner performs near vision measurement by moving the presented visual target to the near distance. When the switch 80h for inputting a signal for shifting to the near vision measurement mode is pressed, a near vision measurement screen is displayed on the monitor 7. FIG. 4 is a display example of the near vision measurement screen 220. In the near vision measurement screen 220, the “ADD” display 221 corresponds to the switch 80d, and a command signal for adding power is added by the switch 80d when the near vision is measured. The visual acuity value UP / DOWN displays 202a and 202b correspond to the switch 80b and the switch 80c. In addition, UP / DOWN displays 224a and 224b for changing the power of addition correspond to the switches 80f and 80g, respectively. The display field 230 on the screen 220 displays the near distance in the near vision measurement. The addition level is displayed in the display field 231 in the center of the monitor 7. In the measurement result display column 240, the correction power values (S, C, A) for distance use are displayed. In the display field 241 next to the display field 240, the value of the objective refractive power measurement result (S, C, A) for near use is displayed.

  When switched to the near vision measurement mode by the switch 80h, the light source 31 and the target plate 32 are moved on the optical axis L2 by driving the drive mechanism 38, and the target presentation distance by the target plate 32 is predetermined. Moved to the near distance. For example, the visual target is set at a position corresponding to a near distance of 33 cm. A near distance of 33 cm corresponds to −3.0 D (diopter) in terms of refractive power. The control unit 70 is as close as 3.0D (diopter) based on the position of the correction power for distance (the correction power for distance determined by the objective refractive power measurement for distance or the visual acuity measurement for distance). The target plate 32 is moved to a position closer to the direction. That is, it is set to a power obtained by adding a spherical power of −3.0D (diopter) to the correction power for distance use. For example, when the distance spherical power of the subject's eye is -2.0D, -3.0D is added to this, and the power at the near distance of 33 cm is -5.0D. It should be noted that when the switch 80h for shifting to the near vision measurement mode is pressed, there is no addition (0.00D). In the near measurement, the astigmatism refraction error is corrected by driving the astigmatism correction optical system based on the result of the distance objective refractive power measurement. Thus, the subject's eye can check the visual target presented at the near distance without being affected by the astigmatic refraction error.

  The examiner confirms the alignment state based on the anterior segment image and the alignment index image of the subject's eye displayed on the monitor 7, and makes the alignment appropriate. When the automatic alignment mode is set, the measurement unit 4 is automatically moved based on the detection result of the alignment index image, and the alignment is made appropriate. Thereafter, the examiner asks the subject whether or not the visual acuity target presented at the near distance 33 cm can be read. The subject's eye uses the eye's accommodation power to confirm the visual target presented at a near distance of 33 cm. At this time, if the alignment state is appropriate, the control unit 70 automatically generates a trigger signal for starting measurement, and performs objective refractive power measurement in near-field measurement. The objective refractive power measurement is performed a plurality of times (for example, three times) to obtain a representative value (for example, an intermediate value) of the measurement result excluding the abnormal data. In the case of manual measurement, the eye refractive power measurement for near use is performed by pressing the measurement start switch 5b.

  The measurement result (S, C, A) of the near-purpose objective eye refractive power is displayed in the display column 241. The control unit 70 compares the spherical power S1 required for the subject's eye to see the near visual target at the set near distance and the spherical power S2 obtained by the near-sighted objective eye refractive power measurement. Then, the difference (S2-S1) is obtained. The spherical power S1 is calculated based on the corrected spherical power for distance use and the power-converted power at the presentation distance of the near vision target. For example, since the corrected spherical power S for distance use is -2.00 D and the presentation distance 33 cm of the near vision target is -3.00 D, the eye of the subject is near vision at the set near distance. The spherical power S1 necessary for viewing the mark is calculated as -5.00D which is the sum of both. When the spherical power S2 obtained by measuring the near-field objective eye refractive power is -5.00D, the difference between S1 and S2 is 0, so that the subject's eye uses the adjustment power. Thus, it is determined that the near vision target is confirmed. In this case, since the addition is not required, the value in the addition display column 231 is set to 0.00D.

  On the other hand, when the spherical power S2 obtained by the near objective optic power measurement is −3.00D, the difference between the two (S2−S1) is + 2.00D. Is judged to have insufficient refractive power for viewing the near vision target. The difference of +2.00 D is displayed in the display field 231 as the addition power.

  The examiner can know whether the addition is necessary for the eye of the subject by checking the addition value displayed in the display field 231. That is, the control unit 70 determines the necessity of the addition in the near vision measurement, and notifies the examiner of the determination result by displaying the addition in the display field 231. As a result, the examiner can determine whether or not to perform the addition measurement step next. In addition, the examiner asks the subject whether or not the visual acuity target can be read. Even if the subject's response is ambiguous because the addition level is displayed in the display field 231. The subject can be urged to make it difficult to interpret the near vision target. When the difference between S1 and S2 (S2−S1) is about ± 0.50D, the eye adjustment lag (the focus position of the original eye is in focus in relation to the depth of focus). In consideration of the phenomenon of moving forward or backward within tolerance, the examiner may be informed that there is a possibility that the addition is not necessary. For example, when the addition level exceeds a certain value (0.50D), a message indicating that the addition level is required may be displayed on the screen.

  If the astigmatism correcting optical system 34 is provided in the optotype presenting optical system 30 as in the above embodiment, the astigmatism refractive power error is corrected and more accurate near vision measurement can be performed. ,preferable. However, the astigmatism correcting optical system 34 is not necessarily required to determine whether or not the addition is necessary for the subject's eye. The subject presented at a predetermined near distance (33 cm, etc.) is focused on the subject's eye, and the subject is set at the near distance set as the spherical power S2 of near power measurement performed in this state. By comparing the spherical power S1 necessary for the eye to see the near vision target, it is determined whether or not the addition degree is necessary for the subject's eye. In this case, as the near spherical power S2, an equivalent spherical power (a value obtained by adding half of the astigmatic power to the spherical power) can be used.

  The examiner confirms the addition value in the display field 231 or a message indicating the necessity of the addition, and proceeds to the near vision measurement step in which the addition is added. When the switch 80d corresponding to the “ADD” display 221 is pressed, the control unit 70 drives the drive mechanism 38 to add the addition power to the correction optical system (target presentation optical system 30), and the near distance ( The target plate 32 is moved in the optical axis direction by an amount corresponding to the addition (difference between S1 and S2) calculated with the position of 33 cm) as a reference. As a result, in the addition measurement for near use, an appropriate initial value of the addition is easily set, and the measurement time for addition adjustment is shortened. That is, the initial value of the addition according to the individual of the subject compared to the case where the initial value of the addition is a constant value as in the conventional case or when the addition is set from the estimation of the age of the subject. Is set appropriately. Note that when the addition is added to the optotype presenting optical system 30, the value of the display 231 blinks.

  The examiner confirms the appearance of the presentation target in a state where the addition degree is added to the subject. When the subject answers that the target is easy to see, it is determined that the addition is appropriate. When the switches 80f and 80g are pressed, the addition applied to the correction optical system is increased or decreased in 0.25D steps. As a result, the examiner finely adjusts the addition according to the subject's eyes. The adjusted addition value is displayed in the display field 231. When the addition degree can be adjusted, the examiner switches the visual acuity values of the visual targets presented by the switches 80b and 80c, and measures the near visual acuity value at the limit of the subject's eyes.

  In addition, after the addition is adjusted, every time the switch 80d corresponding to the “ADD” display 221 is pressed, the state in which the addition is added to the target-presenting optical system and the state in which the addition is removed are alternately displayed. Is switched to. The state in which the addition power is removed is a state in which the astigmatism power is corrected and the spherical power is corrected based on the visual acuity confirmation measurement in the distance (or the measurement result of the eye refractive power in the distance). Thereby, the subject can compare the difference in the appearance of the near vision target depending on the presence or absence of the addition, and can know the necessity of the addition. For this reason, the examiner can easily explain the necessity of the addition at the near distance to the subject.

  The measurement results of the refractive power of the objective and the measurement results of the refractive power and addition of the subjective are used as reference values for precise subjective measurement. By obtaining the measurement results of these awareness by the objective refractive power measurement device, it becomes easy to determine the prescription value in the precise awareness measurement.

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 the switch structure of a switch part, and the display of a monitor. It is a display example of a near vision measurement screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Eye refractive power measurement optical system 10a Projection optical system 10b Receiving optical system 30 Visual target presentation optical system (correction optical system)
70 Control unit 80 Switch unit 100 Objective eye refractive power measurement device 220 Near vision measurement screen 221 “ADD” display 231 display field

Claims (2)

An eye refractive power measuring means for projecting a measurement index onto the fundus of the subject and receiving a reflected light beam from the fundus with a light receiving element to obtain the refractive power of the subject's eye, and a target to be presented to the subject's eye An eye-refractive-index measuring optical system that varies from a distance to a near-distance, and an eye refractive power measurement that obtains a distance power by presenting the target at a distance that is clouded by the target-presenting optical system. In the device
And the near-distance use refractive power measurement means for executing the refractive power measured by Oite the eye refractive power measuring means in a state where target is presented to the predetermined near distance,
Based on the distance refractive power of the subject's eye and the near distance, the subject's eye calculates the refractive power necessary for viewing the target at the near distance, and the calculated refractive power and the near distance Comparing the refractive power for near use obtained by the refractive power measurement execution means, and determining whether or not the eye of the subject needs addition, and notifying the result ,
The determining means, the comparison frequency results examinee's eye when exceeds the predetermined frequency adjustment lugs eye eye refractive power measuring apparatus, characterized that you determined to require additional power.   A correction optical system that corrects astigmatism refractive power and spherical refractive power of a subject's eye, and a target presentation means for presenting a target at a near distance of the subject's eye, the eye of the subject's eye An eye refractive power measuring device for measuring refractive power,
  An eye refractive power measuring means for projecting a measurement index onto the fundus of the subject and receiving a reflected light beam from the fundus with a light receiving element to obtain the refractive power of the subject's eye, and a target to be presented to the subject's eye An optotype eye refractive power measurement device comprising: an optotype presenting optical system that varies from a distance for a distance to a distance for a near distance, wherein the target is presented at the distance for distance or near distance The distance refractive power and the near distance obtained by the objective eye refractive power measuring device for measuring the distance refractive power and the near refractive power by the eye refractive power measuring means, respectively. The subject eye compares the refractive power necessary for viewing the near-distance target and the near refractive power, and determines whether or not the subject eye requires addition power. Judgment means for informing the result, and
  The determination means determines that the subject's eye needs an addition power when the frequency of the comparison result exceeds a predetermined frequency of the eye adjustment lag.