JP6295535B2 - Optometry equipment - Google Patents

Description

  The present invention relates to an optometry apparatus that can subjectively measure the refractive power of an eye to be examined.

  There is known a method of determining the addition power used for the creation of a progressive lens by a subjective examination. For example, in the apparatus described in Patent Document 1, a near vision test can be performed on the eye to be examined whose refractive error is corrected while adding the addition power. In this device, the power of addition that can be added to the eye to be examined is varied, and the near vision test is repeatedly performed, so that the power of addition at which the examiner can see the object existing at the near working distance can be examined.

Japanese Patent Laid-Open No. 10-014874

  Conventionally, when the addition power of the eye to be examined is measured subjectively, a certain fixed value or an estimated value estimated from the age of the subject may be added to the eye to be examined as an initial value of the addition power. there were. In this case, there is a possibility that the initial value of the addition power may deviate from the addition power actually required for the eye to be examined. As the initial value of the addition power is far from the actually required addition power, the time required for measuring the addition power is likely to increase, and the burden on the examiner and the subject is likely to increase.

  An object of the present invention is to provide an optometry apparatus in which the burden on the examiner and the subject is easily suppressed when measuring the addition power of the subject eye in view of the above-described problems of the prior art.

In order to solve the above problem, an optometry apparatus according to the first aspect of the present disclosure includes a correction optical system that corrects a refraction error of an eye to be examined, and corrects the refraction error of the eye to be examined by the correction optical system. An optical optometry apparatus capable of measuring the addition power of the eye, and projecting measurement light toward the fundus of the eye to be examined , and an optical system for presenting the visual target to the eye to be examined. Based on the light reception result of the light receiving element that has received the reflected light, an eye refractive power measuring unit that objectively measures the eye refractive power of the eye to be examined, and a presentation distance changing unit that changes the presentation distance of the target to the eye to be examined And through the measuring operation of measuring the objective eye refractive power at each presentation distance by the eye refractive power measuring means while the presentation distance changing means is changed by the presentation distance changing means, and power, when the adjustment clause of the eye has been demonstrated to the limit Obtains the refracting power, further, two kinds and accommodation power acquisition unit that acquires accommodation power of the eye as the difference of the eye refractive power, the subject's eye when the you subjectively measured addition power of the eye There is provided setting means for setting an initial value of the addition power to be added to the range based on the adjustment force within a range lower than the adjustment force .

  According to the present invention, when measuring the addition power of the eye to be examined, there is an effect that the burden on the examiner and the subject is easily suppressed.

2 is a schematic diagram illustrating a schematic configuration of an optical system and a control system of the optometry apparatus 100. FIG. 3 is a flowchart showing a measurement operation of the optometry apparatus 100. It is the schematic diagram which showed the modification of this invention.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. First, a schematic configuration of an optical system and a control system of the optometry apparatus 100 according to the present embodiment will be described with reference to FIG. In the present embodiment, the optometry apparatus 100 may have an auto-reflective function that objectively measures the refractive power of the eye to be examined. In addition, the optometry apparatus 100 can determine the addition power used for creating a progressive lens. Furthermore, in the optometry apparatus 100, the visual acuity measurement of the eye E to be examined at the distance for distance and the distance for near vision may be performed. The optical system and control system of the optometry apparatus 100 are built in a housing (not shown). The casing may be moved three-dimensionally with respect to the eye E by a known alignment moving mechanism. As illustrated in FIG. 1, the optometry apparatus 100 according to the present embodiment performs measurement for each eye, but may be an apparatus that performs measurement for both eyes simultaneously (in binocular vision). Further, the optometry apparatus 100 may be a handheld type (handy type).

  As shown in FIG. 1, the optometry apparatus 100 includes a measurement optical system 10, a fixation target presentation optical system 30, an alignment index projection optical system 40, and an observation optical system (imaging optical system) 50 as main optical systems. And have.

  The measurement optical system 10 includes a projection optical system (light projecting optical system) 10a and a light receiving optical system 10b. The projection optical system 10a projects a light beam onto the fundus oculi Ef through the pupil of the eye E to be examined. Further, the light receiving optical system 10b takes out a reflected light beam (fundus reflected light) from the fundus oculi Ef through a pupil peripheral portion in a ring shape, and captures a ring-shaped fundus reflection image mainly used for measuring refractive power.

  The projection optical system 10a has a measurement light source 11, a relay lens 12, a hall mirror 13, and an objective lens 14 on the optical axis L1.

  The light source 11 projects a spot-like light source image from the relay lens 11 to the fundus oculi Ef through the objective lens 14 and the pupil center. The light source 11 is moved by the moving mechanism 23 in the direction of the optical axis L1. For this reason, the optometry apparatus 100 according to the present embodiment can measure the refractive power by arranging the light source 11 at a position optically conjugate with the fundus oculi Ef of the normal eye.

  The hall mirror 13 is provided with an opening through which the light beam from the light source 11 through the relay lens 12 passes. The hall mirror 13 is disposed at a position optically conjugate with the pupil of the eye E.

  The light receiving optical system 10b shares the hall mirror 13 and the objective lens 14 with the projection optical system 10a. In addition, the light receiving optical system 10 b includes a relay lens 16 and a total reflection mirror 17. Further, the light receiving optical system 10 b includes a light receiving diaphragm 18, a collimator lens 19, a ring lens 20, and an image sensor 22 on the optical axis L <b> 2 in the reflection direction of the Hall mirror 13. A two-dimensional light receiving element such as an area CCD can be used for the imaging element 22. The light receiving aperture 18, the collimator lens 19, the ring lens 20, and the image sensor 22 are moved in the direction of the optical axis L2 integrally with the measurement light source 11 of the projection optical system 10a by the moving mechanism 23. When the light source 11 is disposed at a position optically conjugate with the fundus oculi Ef by the moving mechanism 23, the light receiving diaphragm 18 and the image sensor 22 are also disposed at positions optically conjugate with the fundus oculi Ef.

  The ring lens 20 is an optical element for shaping fundus reflected light guided from the objective lens 14 through the collimator lens 19 into a ring shape. The ring lens 20 has a ring-shaped lens portion and a light shielding portion. Further, when the light receiving diaphragm 18 and the image sensor 22 are disposed at a position optically conjugate with the fundus oculi Ef, the ring lens 20 is disposed at a position optically conjugate with the pupil of the eye E to be examined. The image sensor 22 receives ring-shaped fundus reflection light (hereinafter referred to as a ring image) via the ring lens 20. The image sensor 22 outputs image information of the received ring image to the control unit 70. As a result, the control unit 70 displays the ring image on the monitor 7, calculates the refractive power based on the ring image, and the like.

  The measurement optical system 10 is not limited to the above, and a light projecting optical system that projects measurement light toward the fundus oculi Ef and a fundus reflection light based on the measurement light from the light projection optical system are received by the light receiving element. And a light receiving optical system. For example, the measurement optical system may be configured to include a Shack-Hartmann sensor as a light receiving element. In addition, other measurement methods may be used in the measurement optical system (for example, a phase difference method device that projects a slit).

  Further, as shown in FIG. 1, in the present embodiment, a dichroic mirror 29 is disposed between the objective lens 14 and the eye E to be examined. The dichroic mirror 29 transmits light emitted from the light source 11 and fundus reflected light corresponding to the light from the light source 11. The dichroic mirror 29 guides a light beam from a fixation target presenting optical system 30 described later to the eye E to be examined. Further, the dichroic mirror 29 reflects the anterior segment reflected light of light from an alignment index projection optical system 40 described later, and guides the anterior segment reflected light to the observation optical system 50.

  As shown in FIG. 1, an alignment index projection optical system 40 is disposed in front of the anterior segment Ec. The alignment index projection optical system 40 mainly projects an index image used for alignment (alignment) of the optical system with respect to the eye E to be examined. The alignment index projection optical system 40 includes a ring index projection optical system 41 and an index projection optical system 42. The ring index projection optical system 41 projects a ring index onto the cornea of the subject's eye E. The ring index projection optical system 41 is also used as anterior ocular segment illumination that illuminates the anterior segment of the subject's eye E in the optometry apparatus 1 of the present embodiment. The index projection optical system 42 projects the infinity index onto the cornea.

  The observation optical system 50 includes an imaging lens 51 and an imaging element 52 on the optical axis L3 in the reflection direction of the half mirror 53. The image sensor 52 is disposed at a position optically conjugate with the anterior segment Ec of the eye E. The image sensor 52 images the anterior segment Ec illuminated by the ring index projection optical system 41. 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 captured by the image sensor 52 is displayed on the monitor 7. Further, in the image sensor 52, an alignment index image (in this embodiment, a ring index and an infinity index) formed on the cornea of the eye E is captured by the alignment index projection optical system 40. As a result, the control unit 70 can detect the alignment index image based on the imaging result of the imaging element 52. In addition, the control unit 70 can determine whether the alignment state is appropriate based on the position where the alignment index image is detected.

  The optotype presenting optical system 30 includes a light source 31, a target plate 32, a relay lens 33, and an astigmatism correcting optical system 34 on the optical axis L <b> 4 in the reflection direction of the reflection mirror 36.

  On the target plate 32, a plurality of targets 32a are arranged in the circumferential direction. The visual target 32a includes a fixation target and a visual acuity test target. The fixation target is used to fix the subject's eye E when measuring objective refractive power. The visual acuity test target is used for a subjective examination. Visual targets for visual acuity values (visual acuity values 0.1, 0.3,..., 1.5) are prepared for the visual acuity test targets. In the present embodiment, the visual target 32a arranged on the optical axis L4 is presented to the eye E by being illuminated by the light source 31. The target plate 32 is connected to a motor 37. When the target plate 32 is rotated by the motor 37, the target 32a arranged on the optical axis L4 is switched. As a result, the visual target 32a presented to the eye E is switched.

  The light source 31 and the target plate 32 (target 32a) are integrally moved in the direction of the optical axis L4 by the drive mechanism 38. By the movement of the light source 31 and the visual target 32a, the presentation position (presentation distance) of the visual target 32a can be optically changed from the far distance to the near distance. Thereby, this apparatus can apply the cloud to the eye E by moving the fixation target at the time of objective refractive power measurement. In addition, this apparatus can correct a refraction error (here, mainly a spherical power error) of the eye E during subjective measurement. In the present embodiment, the spherical power error of the eye E is corrected by the movement of the light source 31 and the target 32a, but is not necessarily limited thereto. For example, an error in spherical power can be corrected by providing a relay lens that can move in the direction of the optical axis L4 in the optotype presenting optical system 30 and moving the relay lens. Alternatively, a plurality of relay lenses having different refractive powers (diopters) may be prepared, and the error of the spherical power may be corrected by switching the relay lenses arranged on the optical axis L4.

  The astigmatism correction optical system 34 has 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 L4 by the rotation mechanisms 35a and 35b, respectively. In the optometry apparatus 100, the astigmatism of the eye E can be corrected by rotating the rotation mechanisms 35a and 35b according to the astigmatic axis angle of the eye E. The correction optical system 34 may have a configuration in which a correction lens is taken in and out of the optical path L4 of the optotype presenting optical system 30. As described above, in the present embodiment, in the optotype presenting optical system 30, the error of the spherical power of the eye E is corrected by the movement of the light source 31 and the optotype 32a, and the cylindrical lenses 34a and 34b are rotated. As a result, the astigmatism of the eye E is corrected. Thus, in this embodiment, the optotype presenting optical system 30 functions as a correction optical system that corrects the refractive error of the eye E to be examined.

  Next, a control system of the optometry apparatus 100 will be described. The optometry apparatus 100 has a control unit 70 as a main control system. The control unit 70 is a processing device having an electronic circuit that performs control processing of each unit of the optometry apparatus 1 and calculation processing of measurement results. The control unit 70 is electrically connected to each of the monitor 7, the movement mechanism 23, the light sources 11 and 31, the image sensors 22 and 52, the rotation mechanisms 35 a and 35 b, the motor 37, the drive mechanism 38, and the operation unit 80.

  The control unit 70 includes a CPU 71, a ROM 72, and a RAM 73. The CPU 71 is a processing device (processor) for executing various processes related to the optometry apparatus 100. The ROM 72 is a nonvolatile storage device that stores a control program and fixed data for the CPU 71 to perform various controls of the optometry apparatus 100. For example, the ROM 72 stores a program for causing the optometry apparatus 100 to execute each step of the flowchart of FIG. The RAM 73 is a rewritable volatile storage device. The RAM 73 stores, for example, temporary data used for measuring and photographing the eye E with the optometry apparatus 100.

  The operation unit 80 includes a measurement start switch 80a, a measurement visual acuity UP switch 80b, a measurement visual acuity DOWN switch 80c, a presentation distance increase switch 80d, a presentation distance decrease switch 80e, and a memory execution switch 80f. Yes. The function of each switch will be described later.

  Next, the measurement operation of the optometry apparatus 100 having the above configuration will be described with reference to the flowchart of FIG. In the present embodiment, when the apparatus is activated, the objective refractive power can be measured. At this time, the CPU 71 sets the fixation target of the target plate 32 on the optical path L4 of the target presentation optical system 30 (S1). The examiner fixes the subject's face to a face support unit (not shown) and causes the eye E to face the optical system of the optometry apparatus 100. The examiner instructs the subject to cause the subject to fixate the fixation target.

  Next, the optical system of the present apparatus is aligned with respect to one eye E of the subject (S2). For example, the CPU 71 causes the alignment index projection optical system 40 to project an alignment index image (in this embodiment, a ring index image and an infinity index image) onto the anterior eye portion Ec. As a result, the anterior segment illuminated by the alignment index projection optical system 40 and the alignment index image projected onto the anterior segment Ec are captured by the imaging element 52 of the observation optical system 50. The CPU 71 detects the alignment state of the present apparatus based on the image information of the anterior segment image and the alignment index image acquired from the image sensor 52. The alignment state in the vertical and horizontal directions is detected based on 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 (front-rear direction) is detected based on the size ratio between the infinity index by the index projection optical system 42 and the ring index image (see JP-A-6-46999). The CPU 71 controls a driving mechanism (not shown) based on the detection results of these alignment index images, and moves the optical system of the present apparatus with respect to the eye E so that the alignment state is appropriate.

  In step S2, the examiner may manually perform alignment of the optical system of the present apparatus. In this case, for example, the CPU 71 causes the monitor 7 to display the anterior segment image and the alignment index image captured by the image sensor 52. Further, the CPU 71 controls the drive mechanism based on an operation received with a joystick or the like, and moves the optical system of this apparatus. Thus, the examiner can align the optical system of the present apparatus by operating the joystick or the like while observing the anterior segment image and the alignment index image of the monitor 7.

  After completion of the alignment, when the examiner presses the measurement start switch 80a, the distance refractive power of the eye E is objectively measured by this apparatus (S3). At this time, the CPU 71 turns on the light source 11. Accordingly, as described above, the imaging element 22 receives the fundus reflection light formed in a ring shape.

  In step S3, first, preliminary measurement of refractive power is performed by the CPU 71. A position conjugate with the fundus oculi Ef on the optical axis L4 is determined based on the refractive power obtained from the preliminary measurement. After placing the fixation target at a position conjugate with the fundus oculi Ef, the CPU 71 moves the fixation target by an appropriate diopter, and applies cloud to the eye E. Thereafter, the actual measurement of the refractive power is performed on the eye E to which the cloud is applied. In the actual measurement, the CPU 71 stores a ring image captured by the image sensor 22 in the RAM 73 as image data (measurement image). Thereafter, the CPU 71 analyzes the ring image stored in the RAM 73 and obtains the value of refractive power in each meridian direction. As a result, the CPU 71 performs a predetermined process on the value of refractive power to obtain an objective value D1 (spherical power S, astigmatism power C, astigmatism axis angle A) of refractive power when the subject eye E is in distance use. obtain. The obtained objective value D1 is stored in the RAM 73. If the refractive power in at least 3 meridian directions can be obtained, the objective values of the spherical power S, the astigmatic power C, and the astigmatic axis angle A can be obtained. Therefore, the measurement optical system is not limited to the configuration using the ring-shaped index image as described above as long as it is an optical system capable of obtaining refractive power in at least three meridian directions.

  Next, in the optometry apparatus 100 according to the present embodiment, the measurement of the adjustment force of the eye E is performed in a state where the refractive error of the eye E is corrected after completion of the objective refractive power measurement for distance use. First, the refraction error of the eye E is corrected (S4). In the present embodiment, the CPU 71 drives the optotype presenting optical system 30 (correcting optical system) based on the objective value D1 of refractive power obtained in the objective refractive power measurement (S3) for distance, so that The refraction error of the optometry E is corrected (corrected). For example, the CPU 71 corrects the error of the spherical power S by moving the light source 31 and the target plate 32 in the direction of the optical axis L4 based on the objective value of the spherical power S at the distance. Further, for example, the CPU 71 drives the two cylindrical lenses 34a and 34b based on the astigmatic power C and the astigmatic axis angle A for distance use, and corrects the astigmatic refraction error.

  In addition, in a state where the refraction error of the eye E is corrected based on the objective value D1, the correction state may be finely adjusted by performing a subjective refractive power test. For example, the CPU 71 places a predetermined visual acuity test target on the optical axis L4 after the objective value D1 for distance use is obtained (for example, a visual target having a visual acuity value of 0.8). The examiner obtains the distance maximum visual acuity value of the eye E based on the response of the subject to the presented visual acuity test target. Here, the examiner selects the switch 80b when the examinee's answer is a correct answer. As a result, the CPU 71 switches the presented visual target to a visual target having a higher visual acuity value. On the other hand, the examiner operates the switch 80c when the subject's answer is an incorrect answer. As a result, the CPU 71 switches the presented visual target to a visual target having a visual acuity value that is one step lower. The examiner can obtain the maximum visual acuity value by repeating the above procedure. When the maximum distance vision value is obtained, the subject is adjusted to the most positive spherical power (weakest frequency) at which the maximum vision value can be obtained. Here, when the switch 80d is pressed, the CPU 71 moves the visual target 32a away from the eye E by a predetermined diopter (for example, 0.25D). On the other hand, the CPU 71 brings the visual target 32a closer to the eye E by a predetermined diopter. Thereby, the correction power (diopter) of the refractive power in the distance is changed. The examiner performs an operation of moving the visual target 32a while confirming the appearance of the subject according to the response from the subject. The distance refractive power (diopter) finely adjusted according to the movement of the target 32a may be used for the following measurement instead of the objective value D1. It should be noted that the weakest spherical power S at which the highest visual acuity can be obtained is a reference value when prescribing a distance correction power such as a spectacle lens or a contact lens.

  Following the step of S4, the adjustment force Fr of the eye E is measured (S5). In the present embodiment, the CPU 71 measures (acquires) the adjustment force Fr of the eye E based on the refractive power measured while the presentation distance of the visual target 32a is changed. Therefore, in the present embodiment, the CPU 71 measures the refractive power of the eye E in real time using the measurement optical system 10.

  In step S5, the CPU 71 further distant by 0.5 diopters on the optical axis L4 from the position corresponding to the objective value D1 obtained in step S3 (that is, the far point of the eye E). Set the fixation target at the position. Thereafter, the CPU 71 drives the drive mechanism 38 to move the fixation target in the vicinity of the eye E. When the adjustment of the eye E is sufficiently performed on the target 32a, the CPU 71 can obtain the refractive power corresponding to the presentation distance of the target 32a from the measurement result by the measurement optical system 10. On the other hand, if the optotype 32a is arranged at a position closer to the eye E than the adjustment near point, it becomes difficult to adjust the eye E with respect to the optotype 32a. For example, the diopter value of refractive power acquired by the CPU 71 And a diopter value corresponding to the presentation distance of the visual target 32a (for example, a value obtained by converting the presentation distance into a diopter) increases. Therefore, by measuring the refractive power while changing the presentation distance of the target 32a, the refractive power when the adjusting power of the eye E is exerted to the limit (hereinafter referred to as "refractive power at near use"). D2 ”) is easily acquired appropriately.

  The CPU 71 stores the refractive power D <b> 2 (spherical power S, astigmatism power C, astigmatism axis angle A) in near-field use in the RAM 73. Further, the CPU 71 obtains the adjustment force Fr of the eye E from the difference between the diopter values of the refractive power D1 and the refractive power D2. The obtained adjustment force Fr is stored in the RAM 73 by the CPU 71.

  In this embodiment, the case where the refractive power is measured while bringing the visual target 32a close to the eye E to measure the refractive power D2 for near vision has been described. By moving the mark 32a away from the eye E, the refractive power D2 for near use can also be measured.

  Next, the process proceeds to step S6. Although details will be described later, in the optometry apparatus 100 according to the present embodiment, the necessity of the addition in the correction device (for example, a spectacle lens) prescribed for the eye E is determined based on the adjustment force Fr of the left and right eyes. Is done. In addition, when performing an examination for determining the addition power (measurement of the addition power), the addition power added to the eye E at the initial stage of the inspection (that is, added to the correction power correction power in the target presentation optical system 30). The added power) is set based on the adjustment force Fr of the left and right eyes. Therefore, in this embodiment, before proceeding to the step (S8) for determining the necessity of addition, the adjustment force Fr of the left and right eyes is measured. In the present embodiment, in step S6, the CPU 71 determines whether or not the measurement of the adjustment force of the eye E has been performed for both the left and right eyes. At this time, for example, the CPU 71 can determine whether or not the measurement of the adjustment force of the eye E has been performed for both the left and right eyes by referring to the adjustment force data stored in the RAM 73. For example, if there is data on the accommodation power for both the left and right eyes in the RAM 73, the CPU 71 can determine that the measurement of the accommodation power has been performed for both the left and right eyes (S6: Yes). On the other hand, if there is only data for the adjustment power for one eye in the RAM 73, the CPU 71 can determine that the measurement of the adjustment power is performed for only one eye (S6: No). In this case, the CPU 71 may output a display for prompting the change of the eye E to be measured to the monitor 7 or the like.

  If the adjustment force is measured for only one eye (S6: No), the eye E to be measured is changed (S7). The examiner operates a joystick (not shown) or the like to roughly align the optical system of the apparatus with the eye E to be examined opposite to the eye E measured so far. Thereafter, when the examiner presses the measurement start switch 80a, the opposite eye E is also measured in steps S1 to S5. As a result, the RAM 73 stores the adjustment power data for the left and right eyes. If the optometry apparatus is a so-called full-auto apparatus that automatically measures both the left and right eyes, the apparatus may automatically move the optical system and change the eye E in step S7.

  On the other hand, when the accommodation power of the left and right eyes is measured at the time of the step of S6 (S6: Yes), whether or not the addition power is necessary for the correction device prescribed for the eye E is determined in the step of S5. The CPU 71 determines based on the acquired adjustment force Fr (S8). For example, the CPU 71 calculates the addition power required to comfortably view an object at a predetermined near working distance, and determines whether or not the calculated addition power is a predetermined value or more (for example, 0D or more). By doing so, it can be determined whether the addition power is necessary. When the predetermined near working distance is N (m), the addition power Add of the eye E can be obtained by the following equation (1), for example.

Add = (1 / N) −Fr × α (where 0 <α ≦ 1) (1)
Here, α indicates the use ratio of the adjusting force. When viewing an object that is away from the eye E by the near work distance N, it is preferable to leave some adjustment force instead of using all adjustment force. For example, when it is assumed that half of the adjustment force is used when viewing a subject away from the eye E by the near work distance N, α = ½. Further, for example, when it is assumed that a 2/3 adjustment force is used when viewing a subject away from the eye E by the near work distance N, α = 2/3. For example, when N = 0.4 m, Fr = 3.0D, and α = 1/2, it can be derived from the result of the above formula (1) that the addition of 1.0D is required. it can.

  Further, the near work distance N and the use ratio α of the adjustment force when the object looks comfortable are different for each subject. Therefore, when the measurement is performed by the present apparatus, the examiner may be allowed to set in advance at least one of the near work distance N and the usage rate α of the adjustment force in the apparatus. For example, the optometry apparatus 100 may be provided with input means for allowing the examiner to input at least one of the near work distance N and the usage rate α of the adjustment power. A value input in advance by the input means may be stored in the RAM 73 and used when the addition power is calculated by the above equation (1). As the input means, for example, a switch such as a numeric keypad, a combination of a GUI and a switch displayed on the monitor 7 can be used. Note that a switch used for inputting the near work distance N or the like may be provided in the operation unit 80.

  In the present embodiment, when the CPU 71 calculates the addition powers of the left and right eyes using Expression (1), and the addition power of 0D or more is calculated for either the left or right eye E, the processing of S9 Proceed to step (S8: Yes). On the other hand, when the addition powers of both the left and right eyes are both 0D or less, the subject can preferably see what is away from the eye E by the near work distance N without adding the addition power. It is considered possible. Therefore, in this case, the measurement is terminated (S8: No).

  When the process proceeds to step S9, the CPU 71 sets an initial value (diopter) of the addition power added to the eye E prior to the subjective test of the addition power (S10). That is, when the optotype presenting optical system 30 is driven by the CPU 71, the addition of the initial value is further added to the correction power of the optotype presenting optical system 30 that corrects the refraction error in the distance for the eye E to be examined. A frequency is added. The initial value of the addition power is set based on the adjustment force Fr acquired in step S5. In particular, in step S9, regardless of whether the subject eye E being measured is left or right, the weaker one of the adjustment forces Fr of the left and right subject eyes E acquired through the step S5 twice. Based on the adjusting force Fr, the CPU 71 sets an initial value of the addition power. Therefore, for example, in the present embodiment, a larger value among the additions Add required for the left and right eye E calculated in the determination step of S8 may be set as the initial value of the addition power. . Further, the CPU 71 reads from the RAM 71 the refractive power D1 of the subject eye E being measured for distance use, and moves the target 32a in the direction of the optical axis L4 based on the refractive power D1 and the initial value of the addition power. Let As a result, in the present embodiment, the visual target 32a is arranged at a position further away from the eye E by the initial value of the addition power from the position where the refraction error in the distance of the eye E is corrected.

  The addition power added to the eye E may be determined in the initial stage of the subjective examination after comparing the difference in the appearance of the visual target 32a depending on the use ratio α of the adjustment force. That is, the initial value of the addition power may be adjusted by changing the use ratio α of the adjustment force. For example, when the initial value of the addition power based on the predetermined usage rate α1 is added to the eye E, the CPU 71 receives a change in the usage rate α. For example, the usage rate α may be changed based on an operation of a switch (not shown) provided in the apparatus. When the CPU 71 accepts the change of the usage ratio α, the CPU 71 acquires the addition power based on the new usage ratio α2, and moves the target 32a based on the addition power. As a result, the eye E is in a state where the addition power based on the new usage rate α2 is added. Thereby, the subject can be compared with the difference in the appearance of the visual target 32a according to the usage rate α of the adjustment force. As a result, by selecting an initial value of the addition that makes it easy for the subject to see the target 32a, it becomes easier to determine an appropriate addition in the subsequent subjective examination. The initial value of the addition power may be adjusted by changing the near work distance N.

  Next, the addition power of the eye E is determined by subjective examination (S10). The examiner confirms with the examinee how the presented target in the eye E looks. For example, when the subject answers that the visual target 32a is easy to see, the examiner can determine that the addition degree added to the eye E is appropriate. When the switches 80d and 80e are pressed, the CPU 71 increases or decreases the presentation position of the visual target 32a in a predetermined step (for example, 0.25D). Thereby, when the subject answers that the target 32a is difficult to see, the examiner can finely adjust the addition power. At this time, the CPU 71 may display the adjusted addition value on the monitor 7. When the addition degree can be adjusted, the examiner switches the visual acuity value of the presented visual target using the switches 80b and 80c, and confirms whether or not the eye E has sufficient near vision.

  When it is confirmed that the eye E has a sufficient near vision value, the examiner operates the memory execution switch 80f. Using the output from the switch 80f as a trigger, the CPU 71 stores the addition power corresponding to the presentation distance of the visual target 32a in the RAM 73. Further, the CPU 71 determines whether or not the addition power of the eye E has been measured for both the left and right eyes (S11). If the addition is measured for only one eye (S11: No), the process proceeds to step S12.

  In step S12, the optical system of the apparatus is moved by the examiner's operation, and the eye E to be measured is changed. Further, when the measurement start switch 80a is pushed by the examiner, the CPU 71 moves the optical system of the apparatus, and moves the optical system of the apparatus and the eye E to be examined for which the addition power has not yet been determined to a predetermined position. Align to relationship. Then, the measurement by the step of S9 and S10 mentioned above is performed. As a result, the RAM 73 stores the awareness value of the addition frequency for the left and right eyes. In this case, the measurement is terminated (S11: Yes).

  As described above, when the addition power of the eye E is measured subjectively, the initial value of the addition power added to the eye E by the optotype presenting optical system 30 is measured by the objective refraction test. Is set based on the adjustment force Fr of the subject eye. Therefore, compared with the case where the initial value of the addition power added to the eye to be examined is set to a certain fixed value or an estimated value estimated from the age of the subject, the optometry apparatus 100 of the present embodiment is more appropriate. A simple initial value of the addition power is easily added to the eye E to be examined. As a result, the optometry apparatus 100 of the present embodiment can easily suppress the burden on the examiner and the subject when the addition power of the eye E is measured subjectively.

  Further, since the CPU 71 objectively measures the refractive power while the presentation distance of the target 32a is changed, the refractive power when the adjustment power of the eye to be examined is exerted to the limit is the objective refractive test. (S5). Since the CPU 71 acquires the adjustment force of the eye E based on the objective value of the refractive power measured by the apparatus in step S5, an appropriate adjustment force is easily acquired. Therefore, in the optometry apparatus 100 of the present embodiment, the initial value of the addition power is easily set based on an appropriate adjustment force.

  In general, it is difficult to suddenly bring the adjustment of the eye E to the limit. On the other hand, in the optometry apparatus 100 of the present embodiment, the refractive power is measured while the target 32a is brought closer to the eye E in step S5. For this reason, it is possible to smoothly increase the adjustment of the eye E according to the approach of the visual target 32a. Therefore, in the optometry apparatus 100, the subject can be easily guided to bring the adjustment of the eye E to the limit in the step of S5. Therefore, in the optometry apparatus 100 of the present embodiment, a more appropriate adjustment force can be easily obtained.

  Further, in the optometry apparatus 100 according to the present embodiment, the fixation target passes the far point of the eye E while the fixation target approaches the eye to be examined in step S5. It is easy to make adjustments follow the fixation target.

  When viewing with both eyes, the adjustment of the eye E tends to work equally on the left and right eyes E. For this reason, if there is a difference between the adjustment forces of the left and right eye E and the addition power of the left and right eye E is determined independently, the left and right eyes can be viewed with both eyes with the addition power added. , Things may be difficult to see.

  On the other hand, in the optometry apparatus 100 of the present embodiment, even if the adjustment force Fr of the eye E acquired by the CPU 71 is different between the left and right eyes E, the initial addition power added to the left and right eyes respectively. The value is set based on the weaker one of the adjustment forces Fr of the left and right eye E (S9). For this reason, in the optometry apparatus 100 according to the present embodiment, even if there is a difference in the adjustment force Fr between the left and right eye E, the addition power that provides good visibility when viewing with both eyes is measured. The person and the subject can easily determine.

  As mentioned above, although demonstrated based on embodiment, it cannot be overemphasized that various deformation | transformation are possible for this invention, without being limited to the said embodiment.

  For example, in the above embodiment, in the subjective test for measuring the addition power, the initial value of the addition power to be added to the eye E is calculated, but the initial value of the addition power is obtained by other methods. Also good. For example, the CPU 71 can set the initial value of the addition power with reference to a table in which the initial value of the addition power is associated with each value of the adjustment force Fr. The table may be stored in the ROM 72 in advance. When the examiner can set at least one parameter of the near work distance N and the use ratio of the adjustment power, the adjustment power Fr and the parameter set by the examiner are associated with the initial value of the addition power. A separate table may be prepared. In the above table, the refractive power D1 and the refractive power D2 may be associated with the initial value of the addition power instead of the adjustment force Fr. As described above, the adjustment force Fr is the difference between the refractive power D1 (objective value D1) for distance use and the refractive power D2 (objective value D2) for near use. In practice, the initial value of the addition power is set based on the accommodation force of the eye E measured by the objective refraction test.

  Moreover, although the said embodiment demonstrated the case where it moved to the subjective measurement (S8-S12) of both eyes after performing the objective measurement (S1-S6) of both eyes, the order of a measurement is not necessarily this order. It is not limited to. For example, after performing the objective measurement and subjective measurement of one eye E, each measurement of the other eye E may be performed. In this case, the CPU 71 of the optometry apparatus 100 determines that the other eye in the subjective examination of the other eye E if the adjustment force of the first eye E measured earlier is smaller than that of the other eye E. You may set the initial value of the addition power set to the optometry E based on the adjustment power of one eye E to be examined. Further, when the adjusting force of one eye E measured earlier is larger than the adjusting force of the other eye E, an addition power that is too weak may be set for one eye E. There is. Therefore, in such a case, re-measurement of the addition degree with respect to one eye E may be performed. For example, when the addition power of both eyes is set by the CPU 71, the CPU 71 determines the difference in the adjustment power between the left and right eyes. As a result, when it is determined that the accommodation power of one eye E measured earlier is smaller than the accommodation power of the other eye E measured later, the addition power of the eye E is again determined. Just measure. In this case, the CPU 71 may display on the monitor 7 or the like to prompt the re-measurement of the addition degree with respect to one eye E. In addition, when re-measurement of the addition power to one eye E is performed, the CPU 71 sets an initial value of the addition power added to one eye E based on the adjustment force of the other eye E. You may do it.

  Moreover, in the said embodiment, the optometry apparatus 100 demonstrated as having both the structure which performs an objective refraction test, and the structure which sets the initial value of the addition power added to the eye E to be examined in a subjective examination. However, the present invention can also be applied to an optometry apparatus that does not have a configuration for performing an objective refraction test as long as the initial value of the addition power can be set based on the accommodation force of the eye to be measured measured by the objective refraction test. For example, the present invention can be applied to the subjective refraction inspection apparatus 200 shown in FIG.

  The subjective refraction inspection apparatus 200 illustrated in FIG. 3 includes a left and right lens unit 201, a control unit 210, an operation unit 220, and a target plate 230. The left and right lens unit 201 includes at least a plurality of spherical correction lenses having different refractive powers, a plurality of cross cylinder lenses, and the like. The left and right lens unit 201 is provided with a pair of inspection windows 202. In the subjective refraction inspection apparatus 200, the refractive error of the eye E is corrected by arranging a spherical correction lens in the inspection window 202. That is, the lens unit 201 has a function as a correction optical system.

  Switching of the lens in the left and right lens unit 201 is controlled by the control unit 210. Based on the operation of the operation unit 220 by the examiner, the control unit 210 can switch the lens disposed in the inspection window 202. When performing the subjective refraction test for determining the addition of the eye to be examined, for example, the objective value D1 of the refractive power for distance use and the adjusting force Fr of the eye E measured by the objective refraction examination device are controlled. The unit 210 may acquire in advance. For example, by transferring the objective value D1 and the adjustment force Fr measured by the objective refraction inspection apparatus to the control unit 210 via the network, the control unit 210 acquires the objective value D1 and the adjustment force Fr. Also good. Further, by connecting the memory storing the objective value D1 and the adjustment force Fr measured by the objective refraction inspection apparatus to the control unit 210, the control unit 210 acquires the objective value D1 and the adjustment force Fr. Also good. The control unit 210 can correct a refraction error in the distance of the eye E by disposing a spherical correction lens corresponding to the spherical power S of the objective value D1 in the inspection window 202. Further, the control unit 210 can correct the astigmatism of the eye E by arranging a cross cylinder lens in the examination window 202 in a manner corresponding to the astigmatism power C and the astigmatism axis angle A of the objective value D1.

  When an inspection start signal is input to the control unit 210 based on an operation performed on the operation unit 220 by the examiner, addition measurement in the present apparatus is started. At this time, the optotype plate 230 is arranged away from the eye E by a near work distance N. The control unit 210 sets an initial value of the addition power based on the accommodation force Fr of the subject eye measured by the objective refraction test. The initial value of the addition power may be obtained using, for example, the above equation (1). The control unit 210 places a spherical correction lens having a power obtained by adding an initial value of the addition power to the spherical power S of the objective value D1 in the inspection window 202. As a result, the examiner can start a subjective examination of the addition power in a state where the addition power corresponding to the initial value is added to the eye E.

  The subjective examination of the addition power in the present modification is performed using a near-field target of cross grid (cross lattice) included in the target plate 230. After the addition value for the initial value is added to the left and right eye E, the control unit 230 drives the plurality of cross cylinder lenses to correct the error of the astigmatic power C. Thereby, for example, an astigmatic power C of + 0.5D is added to the 0-degree axis of the eye to be examined, and an astigmatic power C of -0.5D is added to the 90-degree axis. Thereafter, the examiner increases or decreases the addition power according to the line that appears thicker to the subject among the vertical and horizontal lines of the cross grid. In this measurement, an appropriate addition power is obtained when the vertical line and the horizontal line are seen with the same thickness by the eye to be examined.

DESCRIPTION OF SYMBOLS 10 Refractive power measurement optical system 10a Projection optical system 10b Receiving optical system 30 Target-presenting optical system (correction optical system)
70 Control unit 71 CPU
80 Operation unit 100 Optometry device

Claims (2)

An optometry apparatus that includes a correction optical system that corrects a refraction error of an eye to be examined, and that can correct the refraction error of the eye to be examined by the correction optical system and can subjectively measure the addition power of the eye to be examined.
An optotype presenting optical system for presenting the optotype to the eye to be examined;
Eye refractive power measurement that projects measurement light toward the fundus of the subject's eye and objectively measures the eye refractive power of the subject's eye based on the light reception result of the light receiving element receiving the fundus reflection light of the measurement light Means,
A presenting distance changing means for changing a presenting distance of the target with respect to the eye to be examined;
Through the measurement operation of measuring the objective eye refractive power at each presentation distance by the eye refractive power measuring means while the presentation distance of the target is changed by the presentation distance changing means, , obtains the eye refractive power when the regulatory of the eye has been exerted to the limit, further the accommodation power acquisition unit that acquires accommodation power of the eye as the difference of these two types of eye refractive power,
It comprises a setting means for the initial value of the addition power which is added to the subject's eye when you subjectively measured addition power of the eye, is set based on the accommodation power at low consisting range than the adjustment force An optometry apparatus characterized by comprising: The setting means includes an initial value Add of the addition power, a near working distance N (m) determined for each subject, a value Fr indicating the adjustment force, and a use rate α of the adjustment force determined for each examiner. The optometry apparatus according to claim 1, wherein the optometry apparatus is represented by the following formula (1) using 0 <α <1.
Add = (1 / N) −Fr × α (1)