JP2017060896A - Subjective optometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a subjective optometer capable of measuring an accommodation ability of a subject's eye, with an influence of accommodation convergence reduced.SOLUTION: A subjective optometer includes: a target to be presented to a subject's eye on a measurement optical axis; a measurement optical system including a spherical lens, the spherical diopter of which is changeable in the measurement optical axis; a spherical diopter change unit that changes the spherical diopter of the spherical lens; and an optical axis deflection unit that calculates a deflection angle of the measurement optical axis from the spherical diopter changed by the spherical diopter change unit by using a predetermined formula and deflects the measurement optical axis on the basis of a deflection angle calculated so as to match a visual axis of the subject's eye in which accommodation convergence has occurred. An accommodation ability is measured on the basis of the spherical diopter of the spherical lens in a state where the measurement optical axis is deflected by the optical axis deflection unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a subjective optometry apparatus.

  A subjective optometry apparatus is an apparatus that presents a visual target to an eye to be examined and inspects the visual function of the eye to be examined based on a response from the subject to how the eye is viewed.

  The human eye has a visual function that attempts to clearly see the visual target (to focus on the visual target) by changing the thickness of the crystalline lens. This degree of visual function is the adjusting power. In an adjustment test for measuring an adjustment force using a subjective optometry apparatus, an adjustment test using a method using a spherical lens is performed. In this method, a visual target is presented to the subject's eye, the spherical power of the spherical lens arranged on the measurement optical axis is sequentially changed, and the subject's eye can no longer focus on the visual target. It is a method of measuring the accommodation power of the eye to be examined based on the spherical power at the time of responding "I cannot clearly see the target".

JP 2008-148930 A

  When the human eye is adjusted to increase the thickness of the crystalline lens, convergence occurs in the visual axis (in this specification, the convergence of the visual axis or the optical axis is simply referred to as convergence) (so-called crossed eye state). This congestion occurs unconsciously for the subject, and is a phenomenon called accommodation congestion in the technical field. In the adjustment power test by the method using the spherical lens described above, the eye to be examined adjusts according to the spherical power of the spherical lens, and this adjustability convergence occurs. Then, due to the accommodation convergence, a difference occurs between the measurement optical axis and the visual axis, and this difference makes it difficult for the eye to be examined to fuse the visual target. Therefore, in the adjustment power test by the conventional subjective optometry apparatus, when the subject responds that “the visual target cannot be clearly seen”, the response is caused by insufficient adjustment power of the eye to be examined, or It could not be judged whether it was caused by lack of fusion due to accommodation congestion. In other words, the conventional subjective optometry apparatus has a problem in that the adjustment force of the eye to be examined cannot be measured with suitable accuracy due to the influence of the accommodation convergence.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a subjective optometry apparatus capable of measuring the accommodation force of an eye to be examined while reducing the influence of accommodation congestion. There is to do.

In order to achieve the above object, a subjective optometry apparatus according to claim 1 includes a measurement target including a visual target presented to an eye to be examined on a measurement optical axis and a spherical lens capable of changing a spherical power on the measurement optical axis. System, a spherical power changing unit for changing the spherical power of the spherical lens, and calculating the deflection angle of the measurement optical axis from the spherical power changed by the spherical power changing unit using a predetermined arithmetic expression. An optical axis deflection unit that deflects the measurement optical axis based on the calculated deflection angle so as to match the visual axis of the eye to be examined in which convergence occurs, and the measurement optical axis is adjusted by the optical axis deflection unit. The adjusting force is measured based on the spherical power of the spherical lens in the deflected state.
The invention according to claim 2 is the subjective optometry apparatus according to claim 1, wherein the optical axis deflection unit refracts the measurement optical axis based on the calculated deflection angle. The measurement optical axis is deflected.
The invention according to claim 3 is the subjective optometry apparatus according to claim 1 or 2, wherein the optical axis deflection unit includes a plurality of prism lenses having different prism amounts, and the calculation is performed. And a deflection control unit that arranges a prism lens corresponding to the deflection angle on the measurement optical axis based on the deflection angle.
The invention according to claim 4 is the subjective optometry apparatus according to claim 1, wherein the visual target and the measurement optical system are integrally configured for each of the left eye and the right eye, The optical axis deflecting unit further drives the target optical system based on the calculated deflection angle to deflect the measurement optical axis.
Further, the invention described in claim 5 is the subjective optometry apparatus according to claim 4, wherein the optical axis deflecting unit drives the target optical system based on the calculated deflection angle. A control unit is further provided.

  The subjective optometry apparatus according to the present invention can reduce the influence of the accommodation convergence and can measure the adjustment force of the eye to be examined with suitable accuracy.

It is a block diagram showing the structural example of the subjective optometry apparatus which concerns on embodiment. It is a schematic diagram showing the outline of the subjective optometry apparatus according to the embodiment. It is a schematic diagram showing the outline of the subjective optometry apparatus according to the embodiment. It is a schematic diagram showing the outline of the subjective optometry apparatus according to the embodiment. It is a flowchart showing the operation example of the subjective optometry apparatus which concerns on embodiment. It is a block diagram showing the structural example of the subjective optometry apparatus which concerns on embodiment. It is a schematic diagram showing the outline of the subjective optometry apparatus according to the embodiment. It is a schematic diagram showing the outline of the subjective optometry apparatus according to the embodiment. It is a flowchart showing the operation example of the subjective optometry apparatus which concerns on embodiment.

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

<First Embodiment>
[Constitution]
FIG. 1 is a block diagram showing a configuration of a subjective optometry apparatus according to this embodiment. FIG. 2 is a schematic diagram illustrating a state in which the eye E (the left eye EL and the right eye ER) views the visual target 10 via the measurement optical system 20. FIG. 3 is a schematic diagram showing how the visual axis is congested. FIG. 4 is a schematic diagram showing a state in which the measurement optical axis is matched with the visual axis. In FIG. 4, the measurement optical axis that matches the visual axis is shown at a position shifted from the visual axis, but it is assumed that the measurement optical axis and the visual axis optically match.

  The subjective optometry apparatus 1 includes a visual target 10, a measurement optical system 20, a spherical power changing unit 30, a deflection control unit 40, a control unit 50, and an operation unit 60.

(Target 10)
The visual target 10 is presented to the subject's eye on the measurement optical axis A1 (measurement optical axis A1L related to the left eye and measurement optical axis A1R related to the right eye). The subject views the visual target 10 through a predetermined distance and responds to the appearance. The measurement optical axis A1 is an optical axis for the eye E to visually recognize the visual target 10, that is, an axis representing the center of an optical path where light from the visual target reaches the eye E. The visual target 10 is presented to the eye to be examined by a display device such as a liquid crystal display. The visual target 10 may be presented to the eye to be examined in a form printed on paper.

(Measurement optical system 20)
The measurement optical system 20 refracts light from the visual target 10. The measurement optical system 20 includes a spherical lens 200 and an optical axis deflection unit 210. The spherical lens 200 induces an adjustment force in the eye E. In other words, when the eye E is affected by the spherical lens 200, the eye E is adjusted to thicken the crystalline lens and tries to clearly see the visual target 10. The spherical lens 200 is configured such that the spherical power on the measurement optical axis A1 can be changed. In this configuration, for example, a plurality of spherical lenses 200 having different spherical powers may be inserted into and removed from the measurement optical axis A1.

  The optical axis deflection unit 210 is a prism lens that deflects the measurement optical axis A1 so as to coincide with the visual axis A2 of the eye to be examined (the visual axis A2L of the left eye and the visual axis A2R of the right eye). The visual axis A2 is an axis that passes through the center of the lens L (the lens LL of the left eye and the lens LR of the right eye) and the fovea F (the fovea FL of the left eye and the fovea FR of the right eye). The prism lens is configured such that the prism amount in the measurement optical axis A1 can be changed. In this configuration, for example, a plurality of prism lenses having different prism amounts may be inserted into and removed from the measurement optical axis A1.

(Spherical power changing section 30)
The spherical power changing unit 30 changes the spherical power of the spherical lens 200. For example, when the operator selects a predetermined spherical power using the operation unit 60, the control unit 50 controls the spherical power changing unit 30 to select the spherical power of the spherical lens 200. The configuration may be changed to spherical power. The spherical power changing unit 30 stores the spherical power of the spherical lens 200 in the measurement optical axis A1.

(Deflection control unit 40)
The deflection control unit 40 obtains a deflection angle of the measurement optical axis A1 based on the spherical power of the spherical lens 200, and selects a prism lens corresponding to the deflection angle. The deflection angle is an angle at which the optical axis deflection unit 210 refracts the measurement optical axis A1 in order to make the measurement optical axis A1 coincide with the visual axis A2. The deflection control unit 40 stores in advance related information that associates a selectable prism lens with the prism amount of the prism lens. The deflection control unit 40 receives the output from the spherical power changing unit 30 and acquires the spherical power of the spherical lens 200 on the measurement optical axis A1.

  As described above, when the human eye is affected by the spherical lens, adjustment is performed, and this adjustment causes convergence of the visual axis A2. The amount of convergence due to this adjustable convergence corresponds to the deviation between the measurement optical axis A1 and the visual axis A2, and is expressed as a deflection angle. Therefore, when accommodation convergence occurs, the measurement optical axis A1 is aligned with the visual axis A2 by being deflected by an angle corresponding to the deflection angle.

  It is known as a clinical standard value that when the human eye adjusts the lens by 1D (1 diopter) in the accommodation of accommodation, convergence of the visual axis of 4Δ (4 prism diopter) occurs in both eyes. . Therefore, the spherical power of the spherical lens and the amount of convergence of the eye to be examined are expressed by the following relationship.

  For example, when the spherical power of the spherical lens 200 is −0.25D, the amount of convergence (inward alignment) of the visual axis A2 is 1Δ for both eyes. In this case, the deflection control unit 40 obtains 0.5ΔBO (1Δ out of alignment for both eyes) as a deflection angle for each eye, and calculates a prism lens having a prism amount closest to the change angle based on the related information. The shaft deflection unit 210 is selected. When the optical axis deflecting unit 210 matches the measurement optical axis A1 with the visual axis A2, the eye to be examined can fuse the visual target. As described above, the deflection control unit 40 obtains the deflection angle of the measurement optical axis A1 based on the spherical power of the spherical lens 200, and selects the prism lens based on the obtained deflection angle. In the case of a subject whose AC / A ratio has been measured in advance, the deflection control unit 40 may select a prism lens using the AC / A ratio of the subject instead of the clinical standard value. Good.

  The operator may select a desired prism lens via the operation unit 60 and the control unit 50. When the operator selects a desired prism lens, the display unit 70 may receive the outputs from the spherical power changing unit 30 and the control unit 50 and display the spherical power of the spherical lens.

(Control unit 50, operation unit 60, display unit 70)
The control unit 50 controls the operation of each unit. The control unit 50 includes, for example, a processing device and a storage device. As the processing apparatus, for example, a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), or an ASIC (Application Specific Integrated Circuit) is used. The storage device includes, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and an HDD (Hard Disc Drive). The storage device stores a computer program for executing the function of each unit of the subjective optometry apparatus 1. The processing device implements the control process by executing these computer programs. The operation unit 60 is used by an operator to operate the subjective optometry apparatus 1. The operation unit 60 includes various hardware keys (buttons, switches, etc.) provided on the housing of the subjective optometry apparatus 1 or the like. When a touch panel display or GUI is provided, the operation unit 60 also includes various software keys displayed on the touch panel display or GUI. The display unit 70 displays information such as the spherical power of the spherical lens 200 and the prism amount of the prism lens. The display unit 70 is configured by a display device such as a liquid crystal display.

[Operation]
The operation of the subjective optometry apparatus of this embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of the subjective optometry apparatus 1.

(S01)
The control unit 50 controls the visual target 10 to present the visual target 10 to the eye to be examined on the measurement optical axis A1.

(S02)
The control unit 50 controls the spherical power changing unit 30 to change the spherical power of the spherical lens 200.

(S03)
The control unit 50 controls the deflection control unit 40 to obtain the deflection angle of the measurement optical axis A1 based on the spherical power of the spherical lens 200.

(S04)
The control unit 50 controls the deflection control unit 40 to select a prism lens corresponding to the deflection angle.

(S05)
As the deflection control unit 40 selects the prism lens, the measurement optical axis A1 coincides with the visual axis A2.

(S06, S07)
When it is necessary to further change the spherical power of the spherical lens 200, the control unit 50 performs the operation of step S02. When it is not necessary to further change the spherical power of the spherical lens 200, the subjective optometry apparatus 1 measures the accommodation power of the eye to be examined based on the spherical power of the spherical lens 200.

[Action / Effect]
The operation and effect of this embodiment will be described.

  The subjective optometry apparatus 1 includes a visual target 10, a measurement optical system 20, a spherical power changing unit 30, and an optical axis deflecting unit 210. The visual target 10 is presented to the eye E to be examined on the measurement optical axis A1. The measurement optical system 20 includes a spherical lens 200 whose spherical power can be changed. The spherical power changing unit 30 changes the spherical power of the spherical lens 200. The optical axis deflecting unit 210 deflects the measurement optical axis A1 so as to coincide with the visual axis A2 of the eye E. The optical axis deflecting unit 210 may be a prism lens that deflects the measurement optical axis A1 to match the visual axis A2. The subjective optometry apparatus 1 may further include a deflection control unit 40. The deflection control unit 40 obtains a deflection angle of the measurement optical axis A1 based on the spherical power of the spherical lens 200, and selects a prism lens corresponding to the deflection angle. Accordingly, the subjective optometry apparatus 1 measures the adjustment force based on the spherical power of the spherical lens 200 in a state where the measurement optical axis A1 is deflected by the optical axis deflecting unit 210. As described above, the subjective optometry apparatus 1 measures the adjustment force of the eye E in a state where the measurement optical axis A1 is aligned with the visual axis A2, that is, in a state where the eye E is fused with the visual target 10. Can do. Therefore, it is possible to provide a subjective optometry apparatus that can reduce the influence of accommodation convergence and measure the adjustment force of the eye E.

<Second Embodiment>
FIG. 6 is a block diagram showing the configuration of the subjective optometry apparatus according to this embodiment. This embodiment differs from the first embodiment in the configuration of the visual target, the measurement optical system, and the optical axis deflecting unit. Other configurations are the same as those of the first embodiment. FIG. 7 is a schematic diagram showing a state in which the eye E (the left eye EL and the right eye ER) views the visual target 10 via the measurement optical system 20. FIG. 8 is a schematic diagram showing a state in which the measurement optical axis is matched with the visual axis. In FIG. 8, the measurement optical axis matched with the visual axis is shown at a position shifted from the visual axis, but it is assumed that the measurement optical axis and the visual axis are optically matched.

  The subjective optometry apparatus 1 has a target optical system 2. The target optical system 2 includes the target 10 (left eye system target 10L, right eye system target 10R) and the measurement optical system 20 (left eye system measurement optical system 20L, for each of the left eye EL and the right eye ER. The right-eye system measurement optical system 20R) is integrally formed and can be further driven. The measurement optical system 20 includes a spherical lens 200 (a left-eye spherical lens 200L and a right-eye spherical lens 200R) that can change the spherical power on the measurement optical axis A1. The left eye system target 10L and the right eye system target 10R are indices that are presented only to the left eye EL and the right eye ER, respectively. The target optical system 2 optically creates a distance between the target 10 and the eye E. The optotype optical system may be configured, for example, by using an optical device configuration of a general optometry apparatus with a built-in left and right eye independent optotype.

  The optical axis deflection unit 41 deflects the measurement optical axis A1 so as to coincide with the visual axis A2 of the eye E. The optical axis deflecting unit 41 is a driving unit that drives the target optical system 2. This drive means may be comprised by general mechanical mechanisms, such as a motor and a gearwheel, for example.

  The deflection control unit 40 obtains the deflection angle of the measurement optical axis based on the spherical power of the spherical lens 200, and drives the target optical system 2 to the optical axis deflection unit 41 based on the deflection angle. The deflection control unit 40 receives the output from the spherical power changing unit 30 and acquires the spherical power of the spherical lens 200 on the measurement optical axis A1.

  The calculation of the driving amount in this driving will be described using the above-described clinical standard value of the amount of accommodation convergence in the human eye. The relationship between the spherical power of the spherical lens 200 and the amount of convergence of the visual axis A2 is expressed by the above-described [Equation 1]. Further, the prism amount of 1Δ is an amount by which the image 1 meter ahead is displaced by 1 centimeter. Therefore, the deflection angle of the measurement optical axis A1 is expressed by the following equation.

  For example, when the spherical power of the spherical lens 200 is −1D, the deflection angle of the measurement optical axis A1 is 0.02 rad. In this case, the optical axis deflection unit 41 calculates 0.02 rad as a driving amount for each eye, and causes the optical axis deflection unit 41 to drive the target optical system 2. By this driving, the measurement optical axis A1 is aligned with the visual axis A2. Note that in the case of a subject whose AC / A ratio has been measured in advance, the optical axis deflection unit 41 uses the AC / A ratio of the subject instead of the clinical standard value. The amount of congestion may be determined.

  Further, the operator may select a desired drive amount via the operation unit 60 and the control unit 50. When the operator selects a desired driving amount, the display unit 70 may receive the outputs from the spherical power changing unit 30 and the control unit 50 and display the spherical power of the spherical lens.

[Operation]
The operation of the subjective optometry apparatus of this embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing the operation of the subjective optometry apparatus 1.

(S01)
The control unit 50 controls the visual target 10 to present the visual target 10 to the eye to be examined on the measurement optical axis A1.

(S02)
The control unit 50 controls the spherical power changing unit 30 to change the spherical power of the spherical lens 200.

(S03)
The control unit 50 controls the deflection control unit 40 to obtain the deflection angle of the measurement optical axis A1 based on the spherical power of the spherical lens 200.

(S04)
The control unit 50 controls the deflection control unit 40 to cause the optical axis deflection unit 41 to drive the target optical system 2.

(S05)
When the optical axis deflecting unit 41 drives the target optical system 2, the measurement optical axis A1 is aligned with the visual axis A2.

(S06, S07)
When it is necessary to further change the spherical power of the spherical lens 200, the control unit 50 performs the operation of step S02. When it is not necessary to further change the spherical power of the spherical lens 200, the subjective optometry apparatus 1 measures the accommodation power of the eye to be examined based on the spherical power of the spherical lens 200.

[Action / Effect]
The operation and effect of this embodiment will be described.

  The subjective optometry apparatus 1 includes a target optical system 2, a spherical power changing unit 30, and an optical axis deflecting unit 41. The target optical system 2 includes the target 10 and the measurement optical system 20 individually and integrally for each of the left eye and the right eye. The target optical system 2 optically creates the distance between the target 10 and the eye E for the left eye and the right eye. The visual target 10 is presented to the eye E to be examined on the measurement optical axis A1. The measurement optical system 20 includes a spherical lens 200 whose spherical power can be changed. The spherical power changing unit 30 changes the spherical power of the spherical lens 200. The optical axis deflection unit 41 deflects the measurement optical axis A1 so as to coincide with the visual axis A2 of the eye E. Further, the optical axis deflection unit 41 may be a driving unit that drives the target optical system 2. The subjective optometry apparatus 1 may further include a deflection control unit 40. The deflection control unit 40 obtains the deflection angle of the measurement optical axis A1 based on the spherical power of the spherical lens 200, and drives the target optical system based on the deflection angle. Accordingly, the subjective optometry apparatus 1 measures the adjustment force based on the spherical power of the spherical lens 200 in a state where the measurement optical axis A1 is deflected by the optical axis deflecting unit 41. As described above, the subjective optometry apparatus 1 can measure the adjustment force of the eye E in a state where the measurement optical axis A1 is aligned with the visual axis A2, that is, in a state where the eye to be examined has fused the visual target 10. it can. Therefore, it is possible to provide a subjective optometry apparatus that can reduce the influence of accommodation convergence and measure the accommodation power of the subject's eye.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Subjective optometry apparatus 2 Target optical system 10 Target 10L Left eye system target 10R Right eye system target 20 Measurement optical system 20L Left eye system measurement optical system 20R Right eye system measurement optical system 30 Spherical power change part 40 Deflection Control unit 41 Optical axis deflection unit 50 Control unit 60 Operation unit 70 Display unit 200 Spherical lens 200L Left eye system spherical lens 200R Right eye system spherical lens 210 Optical axis deflection unit A1 Measurement optical axis A1L Measurement optical axis A1R Measurement optical axis A2 Viewing Axis A2L visual axis A2R visual axis E eye to be examined EL left eye ER right eye F fovea FL fovea FR fovea L lens LL lens LR lens

Claims (5)

A visual target presented to the subject's eye on the measurement optical axis;
A measurement optical system including a spherical lens capable of changing the spherical power on the measurement optical axis;
A spherical power changing section for changing the spherical power of the spherical lens;
The deflection angle of the measurement optical axis is calculated from the spherical power changed by the spherical power changing unit using a predetermined arithmetic expression, and the calculation is performed so as to match the visual axis of the eye to be examined in which the accommodation convergence has occurred. An optical axis deflecting unit that deflects the measurement optical axis based on a deflection angle;
Have
A subjective optometry apparatus that measures adjustment force based on the spherical power of the spherical lens in a state in which a measurement optical axis is deflected by the optical axis deflecting unit. The subjective optical optometry apparatus according to claim 1, wherein the optical axis deflecting unit deflects the measurement optical axis by refracting the measurement optical axis based on the calculated deflection angle. The optical axis deflection unit includes a plurality of prism lenses having different prism amounts,
The subjective optometry apparatus according to claim 1, further comprising: a deflection control unit configured to arrange a prism lens corresponding to the deflection angle on the measurement optical axis based on the calculated deflection angle. . For each of the left eye and the right eye, the target and the measurement optical system are integrally configured, and further includes a target optical system that can be driven,
The subjective optical optometry apparatus according to claim 1, wherein the optical axis deflecting unit deflects the measurement optical axis by driving the target optical system based on the calculated deflection angle. The subjective optometry apparatus according to claim 4, further comprising a deflection control unit that causes the optical axis deflection unit to drive the target optical system based on the calculated deflection angle.

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