JP2001000394A - Optometrical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optometrical device capable of automatically measuring the regulating power of an examined eye accurately and rapidly. SOLUTION: This optometrical device 100 is provided with an eye refractivity detecting system 10 by irradiating an examined eye 1 with infrared rays and obtaining a signal indicating refractivity on the basis of the reflected light, a fogging optical system 20 moving a fixation table far and near selectively along the direction of an optical axis L1, and a computer 31. The computer 31 determines the moving quantity of the fixation table 2 on the basis of signals from the eye refractivity detecting system varied in association with the movement of the fixation table 2, and obtains far sight refractivity and near sight refractivity on the basis of the moving quantity of the fixation table 2 moved by the fogging optical system 20 and refractivity varied by this movement. The computer 31 further obtains the regulating power of the examined eye on the basis of these values. A far sight refractivity measuring fixation table (a first fixation table) and a near sight refractivity measuring fixation table (a second fixation table) are prepared as the fixation table 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optometric apparatus and, more particularly, to an optometric apparatus which can objectively measure the refractive power of an eye to be examined.

[0002]

2. Description of the Related Art Conventionally, an optometric apparatus (objective eye refractive power measuring apparatus) for measuring an eye refractive power of a person to be measured is known, for example, from Japanese Patent Application Laid-Open No. Hei 6-233740. This conventional optometry apparatus irradiates measurement light to the eye (eye to be inspected) and measures the refractive power of the eye to be inspected based on the reflected light while the person to be measured is fixing the fixation table. Things.

[0003] In this case, the subject attempts to capture a fixation table moving (moving away) along the optical axis direction of his or her own eye, and the subject's eye moves due to the refractive power of the lens of the subject's eye accompanying the movement. The refractive power measuring device objectively automatically measures the refractive power of the eye to be examined in far vision.

[0004]

In ophthalmological examinations, there is a demand for measuring not only the refractive power for far vision but also the accommodation power of the eye to be examined. The accommodation power of the eye to be examined is generally obtained by comparing the refractive power for far vision and the refractive power for near vision.

[0005] Here, the far vision refractive power is automatically measured by the above-mentioned optometer, but the near vision refractive power is still measured.
The value was calculated artificially. That is, the fixation table is fixed by the subject, and the fixation table is brought closer to the subject side in that state, and the fixation table when the subject is determined to be unable to accurately recognize the image of the fixation table. And the near-view refractive power was determined from this position.

As described above, when the accommodation power of the eye to be examined is determined by an ophthalmic examination, even if the distance vision refractive power is determined by an objective automatic measurement, the measured value of the near vision refractive power which is artificially performed includes: Still, there is a problem that the subject's subjectiveness is still present, an accurate value cannot be obtained, and the accommodation power of the subject's eye cannot be measured accurately. The present invention has been made in view of such circumstances, and an object of the present invention is to provide an optometric apparatus that can objectively, easily, and automatically measure the accommodation power of an eye to be examined.

A further object of the present invention is to provide an optometric apparatus which can determine the accommodation power of an eye to be examined in a short time.

[0008]

According to a first aspect of the present invention, there is provided an optometry apparatus which irradiates a measurement light to a subject's eye and outputs a signal indicating a refractive power of the subject's eye based on the reflected light. Eye-refractive-power detecting means for outputting a fixation table, and a fixation-table moving means for selectively moving a fixation table in a first direction away from the subject's eye and a second direction approaching the subject's eye along the optical axis direction of the subject's eye. Moving amount control means for determining a moving amount of the fixation table by the fixation table moving means based on a signal from the eye refraction power detecting means which changes with movement of the fixation table; Far vision refractive power detecting means for obtaining far vision refractive power based on the amount of movement when the fixation table is moved in the first direction by the moving means and a signal from the eye refractive power detecting means which is changed by the movement; And the fixation table is moved in the second direction by the fixation table moving means. Near vision refractive power detecting means for obtaining near vision refractive power based on the amount of movement when moving and a signal from the eye refractive power detecting means changed by this movement, and the obtained far vision refractive power and An accommodating force detecting means for acquiring an accommodating force of the eye to be examined based on the obtained near vision refractive power.

According to a second aspect of the present invention, in the optometry apparatus, the distance vision refracting power detector detects the distance of movement of the fixation table in the first direction by the fixation table moving unit. The distance vision refractive power is determined from the value of the refractive power when the change width of the refractive power indicated by the signal from the eye refractive power detection means is equal to or less than a certain value, and the near vision refractive power detection means is the fixation table. The value of the refractive power when the change width of the refractive power indicated by the signal from the eye refractive power detecting means with respect to the amount of movement when the fixation table moves in the second direction by the moving means is equal to or less than a certain value. Is used to determine the refractive power for near vision.

According to a third aspect of the present invention, in the optometry apparatus, the far vision refracting power detecting means moves the fixation table in the first direction by the fixation table moving means. The distance vision refractive power is determined from the position of the fixation table when the change width of the refractive power indicated by the signal from the eye refractive power detection means is equal to or less than a certain value, and the near vision refractive power detection means performs the fixation. The fixation table when the change width of the refractive power indicated by the signal from the eye refractive power detection means with respect to the movement amount when the fixation table moves in the second direction by the table moving means is equal to or smaller than a certain value. Is used to determine the near-view refractive power.

According to a fourth aspect of the present invention, in the optometry apparatus, the fixation table moving means includes: a first fixation table moved in the first direction as the fixation table; And a second fixation table moved in the direction.

(Function) According to the first aspect of the present invention, since both of the refractive power for far vision and the refractive power for near vision can be objectively and automatically measured, the accommodation power of the eye to be examined is objectively obtained. be able to.

According to the second aspect of the present invention, the change in the refractive power of the eye to be examined which follows the movement of the fixation table is objectively determined, and the distant distance determined based on the change in the refractive power is determined. The accommodation power of the subject's eye can be obtained in a short time and objectively from the visual refractive power and the near visual refractive power. According to the third aspect of the present invention, a change in refractive power (a change in refractive power for far vision and a change in refractive power for near vision) of the eye to be examined which follows the movement of the fixation table is monitored, and the change is monitored. The accommodation power of the eye to be inspected can be easily obtained only by obtaining the position of the fixation table when the width of is smaller than a certain value.

Further, according to the invention of claim 4, it is possible to make the subject to know which of the refractive power for far vision and the refractive power for near vision is being measured.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This embodiment corresponds to claims 1, 2, and 4.

First, the overall configuration of the optometry apparatus 100 will be described with reference to FIG. As shown in FIG. 1, the optometry apparatus 100 includes an eye refractive power detection system (eye refractive power detection means) 1
0, a fog optical system (fixation table moving means) 20, a feedback control unit 30, a measurement result display unit 40, and an imaging optical system 50. Of these, the eye refractive power detection system 10 irradiates the subject's eye 1 with measurement light (infrared light), and reflects the reflected light inside a light receiving element (photoelectric conversion elements 19a and 19b described later).
Etc.). A signal indicating the detection result from the light receiving element (an electric signal corresponding to the refractive power of the eye 1 to be inspected) is converted into a digital signal, and then output to the computer 31 of the feedback control unit 30.

The fog optical system 20 includes a fixation table moving unit 2.
1. Projection lens 22, diaphragm 23, mirror 24, lens 2
The imaging optical system 50 includes a half mirror 26, a dichroic mirror 27, a lens 28, and an imaging surface 29. When the subject is fixating on the fixation table 2 attached to the fog optical system 20, an image of the fixation table 2 illuminated from behind by the visible light source 21b passes through the projection lens 22 and the aperture 23. To the mirror 24, and after being reflected by this mirror 24, through a lens 25 and a half mirror 26,
The light reaches a dichroic mirror (having infrared light transmission and visible light reflection characteristics) 27, and after being reflected by the dichroic mirror 27, an image is formed on the retina of the subject's eye 1. Here, the lens 25 is for positioning the stop 23 at a position optically conjugate to the pupil of the eye 1 to be inspected.
In other words, the action of the lens 25 causes the eye 1 to be inspected.
, The size of the light beam entering the pupil can be kept optically constant, and the depth of field of the image can be kept constant.

Here, if the refraction state of the eye 1 to be examined is in a certain state, the fixation table 2 formed on the retina of the eye 1 to be examined.
Is only one point on the optical axis L1. That is, the position on the optical axis L1 of the fixation table 2 that forms an image on the retina of the subject's eye 1 and the refractive power (DH) of the subject's eye 1 have a one-to-one relationship. The state of the subject's eye 1 when the image of the fixation table 2 is formed is projected on the imaging surface 12 via the half mirror 26 and the lens 28, and the subject's eye 1 is observed and photographed.

When the fixation table 2 is moved rightward (distant) in the figure along the optical axis L1 from the state where the image of the fixation table 2 is formed on the subject's eye 1, the fixation table 2 is fixed. Eye 1
Attempts to follow the movement of the image of the fixation table 2. At this time, the eye-adjusting power of the subject's eye 1 is relaxed. Here, the fixation table 2 is moved to a predetermined distance by a distant distance, so that the refractive power (distant vision refractive power) of the eye to be examined 1 corresponding to the movement amount (movement width) of the fixation table 2 is determined. The change is detected by the eye refractive power detection system 10 and the computer 31. When the fixation table 2 is moved far, the image of the fixation table 2 is formed slightly ahead of the retina of the subject's eye 1 so that the subject's eye 1 naturally points far away. Thus, the subject's eye 1 is relaxed.

Further, in the fogging optical system 20, the fixation table 2 is moved along the optical axis L1 in the leftward direction (closer direction) from the state where the image of the fixation table 2 is formed on the eye 1 to be inspected. Can also be moved. When the fixation table 2 is moved to the near side, the eye to be inspected 1 that is fixating on the fixation table 2 becomes in a direction in which the visual acuity adjusting force is tense. Here, by moving the fixation table 2 to a predetermined movement amount, a change in the refractive power of the eye 1 to be examined corresponding to the movement amount (movement width) of the fixation table 2 is detected by an eye refractive power detection system. 10 and the computer 31 detect.

Here, the fixation table moving unit 21 includes a holding unit 21a to which the fixation table 2 is attached, a visible light source 21b for irradiating visible light from the back side of the fixation table 2, and a holding unit 21a which is connected to the optical axis L.
1 is provided with a stage 21c for moving in a distant (first direction) and near (second direction) directions. When a drive signal from the feedback control unit 30 is input to the stage unit 21c, the built-in pulse motor 21d operates, and the holding unit 21a moves a predetermined movement width (movement amount) according to the drive signal. Just to move.

In the fixation table moving section 21, a fixation table (first fixation table) 2A for measuring the distance vision refractive power is provided as the fixation table 2.
And a fixation table (second fixation table) 2B for refractive power measurement for near vision. Here, as the fixation table 2A, “a landscape with one tree in a wide grassland” (FIG. 2A) can be considered. On the other hand, as the fixation table 2B, a “table in which a character string is described in the center” (FIG. 2B) can be considered.

By preparing the fixation table 2A, at the time of measuring the refractive power for far vision, the subject is given the feeling of looking far away, and the tension of the eye 1 is relaxed. And a more accurate measurement of the distance vision refractive power can be obtained. Conversely, by preparing the fixation table 2B, the subject can be given a feeling of reading, and the tension of the eye 1 can be maintained.
More accurate measurements of near vision refractive power can be obtained.

The feedback control section 30 comprises a computer 31 (which functions as a moving amount control means, a refractive power detecting means for far vision, a refractive power detecting means for near vision, and an adjusting power detecting means) and a drive circuit 32. The computer 31 moves the fixation table 2 of the fog optical system 20 based on a signal from the eye refractive power detection system 10 (an electrical signal corresponding to the refractive power of the eye 1 to be examined), as described in detail later. The control signal indicating the movement width (movement amount in one loop) is output from the drive circuit 3
2 is output. The drive circuit 32 generates a drive signal based on the control signal and outputs the drive signal to the pulse motor 21d of the stage 21c.

On the other hand, the computer 31 changes the control signal and the change in the signal from the eye-refractive-power detection system 10 obtained after the fixation table 2 is actually moved based on the control signal (the fixation table 2). (The degree of change in the refractive power of the eye 1 to be followed). Then, the computer 31 compares the movement of the fixation table 2 (one movement width) with the degree of change in the refractive power corresponding to the movement. This comparison is performed separately when the fixation table 2 is moved to a distance and when the fixation table 2 is moved to the near side. The distance vision refractive power (DH1) and the near vision refractive power (DH2) are: Required individually. The computer 31 compares the distance vision refractive power (DH1) with the near vision refractive power (DH2) to obtain the accommodation power (D
C) is automatically determined.

In this embodiment, the computer 31
Is that even if the fixation table 2A is moved so that the eye to be examined 1 is directed to the far point (far), the eye to be examined 1 is most relaxed and changes its refractive power (DH) (for example, 0.06D or less). The value when no longer appears is referred to as far vision refractive power (DH1). Further, even if the computer 31 moves the fixation table 2B so that the eye to be examined 1 is directed to the near point (near), the eye to be examined 1
Is the most nervous and changes its refractive power (DH) (0.06D
Is less than the value when near vision refractive power (DH)
2)

The measurement result display section 40 connected to the computer 31 comprises a CRT controller 41 and a CRT 42. The CRT controller 41 has a far vision refractive power (DH1) obtained by the computer 31 and
A command signal indicating near vision refractive power (DH2) and accommodation power (DC) is input. The CRT controller 41 gives the CRT 42 a far vision refractive power (DH1), a near vision refractive power (DH2), and an accommodation power (DC) based on these input command signals.
Is displayed. In addition, the obtained far vision refractive power (DH1)
/ Near vision refractive power (DC2) / adjustment power (DC) can also be output by a printer or the like (not shown).

Next, an outline of the eye refractive power detecting system 10 will be described with reference to FIG. The measurement principle of the eye-refractive-power detection system 10 is based on a radiographic method, and measures the eye refractive power by detecting the speed of the movement of a shadow on the pupil of the subject's eye 1. An objective eye refractive power detector using this contrast analysis method is known, for example, from JP-A-55-86437.

The eye refractive power detection system 10 of this embodiment is
Measurement meridian rotation system 10A, chopper 10B, light receiving unit 10C
And is constituted by. Here, the measurement meridian rotation system 10
A is for detecting the astigmatic state of the eye 1 to be inspected. At the time of detecting the eye refractive power of the subject's eye 1, infrared light is emitted from the light emitting diode 11 in the chopper 10B, and an image of this infrared light is formed in the pupil of the subject's eye 1 by the action of the condenser lens 12. You.

A plurality of slit openings are formed along the circumference of the cylinder 13 of the chopper 10B.
When the 0B cylindrical body 13 rotates around the light emitting diode 11, the linear light flux transmitted through the slit opening S is reflected by the half mirror 14 toward the eye 1 to be inspected. The linear light flux reflected by the half mirror 14 is incident on the eye 1 through the prism 15 and the mirror 16 of the measurement meridian rotation system 10A.

The linear luminous flux reaching the eye 1 is reflected by the eye 1, and the reflected light is transmitted through the measuring meridian rotation system 10A, the half mirror 14, the objective lens 17, and the diaphragm 18.
The light reaches the light receiving surface of the light receiving unit 10C, and an image of the pupil plane of the subject's eye 1 is formed by the light receiving unit 10C.

On the substrate of the light receiving unit 10C, photoelectric conversion elements (light receiving elements) 19a and 19b and a four-division photoelectric conversion element (not shown) for detecting a positional shift are arranged. A change in the brightness of the formed image is detected by the photoelectric conversion elements 19a and 19b. By measuring the phase difference between the signals output from the two photoelectric conversion elements 19a and 19b, the refractive power of the eye 1 is detected.

The electric signals from the photoelectric conversion elements 19a and 19b are converted into digital signals by an A / D converter (not shown) of the signal processing unit 19c and then input to the computer 31. Note that a method of detecting the refractive power of the eye 1 to be inspected by the eye refractive power detection system 10 (a procedure of processing an electric signal in the eye refractive power detection system 10) is known in, for example, Japanese Patent Application Laid-Open No. 6-233740. Yes, and the specific description is omitted.

Next, the computer 31 of the optometry apparatus 100
The procedure of the automatic measurement of the distance vision refractive power (DH1) / near vision refractive power (DH2) / adjustment power (DC) of the subject eye 1 will be described with reference to the flowchart of the measurement program shown in FIG. Prior to the automatic measurement of the distance vision refractive power (DH1) / near vision refractive power (DH2) / adjustment power (DC) of the subject's eye 1, the subject measures the subject's eye 1 formed on the imaging surface 29 of FIG.
Based on the image of the subject, there is no displacement between the subject's eye 1 and the optometry apparatus 100 (the optical axis of the subject's eye 1 matches the optical axis L1 of the optometry apparatus 100), and the eyelashes and the like of the subject Check that it is not in the measurement optical path. And after confirmation, the measurer
When a measurement start switch (not shown) is turned on, a CPU (not shown) in the computer 31 executes the measurement program (FIG. 4).

When the measurement program is started, first, in step S1, a fixation table 2A for far vision refractive power measurement is selected in order to automatically measure the far vision refractive power (DH1). In this measurement program, the distance vision refractive power (DH
After the automatic measurement of 1), the automatic measurement of the refractive power for near vision (DH2) is performed. This is the optometry device 100
This is because mechanical myopia occurs when the refractive power of the eye to be examined is measured by, and it is necessary to first automatically measure the distance vision refractive power (DH1), which is greatly affected by a measurement error due to mechanical myopia. The automatic measurement of the distance vision refractive power (DH1) is performed during a period (preferably 1.0
To 2.0 seconds). On the other hand, automatic measurement of near vision refractive power (DH2) is performed by mechanical myopia,
Even if the person becomes nervous, there is almost no effect on the measured value.

When the fixation table 2A is selected in step S1, the fixation table 2A is moved to the initial position in the fixation table moving section 21 (step S2). This initial position is, for example, within a range of about -4 diopters (clear visual distance) (approximately about 25 cm from the subject's eye 1). In the next step S3, the apparent movement amount “L” (movement width) of the fixation table 2A is set to its initial value of 1.0 diopter (D). The actual amount of movement of the fixation table 2A depends on the fog optical system 20.
The value is determined by the optical system inside. When the value of “L” is positive, the fixation table 2 moves to the far side.

In step S4, the fixation table 2A is moved according to the movement amount "L" set at this time. In step S5, the refractive power (DH) of the subject's eye 1 is determined based on the signal obtained by the eye refractive power detection system 10, and the refractive power (DH) thus determined is set to a previous value (initial value in the first loop). Value), and the amount of change (ΔD
H) is detected. When the accommodation power of the subject's eye 1 is sufficient,
This change amount (ΔDH) corresponds to the movement amount “L”.

In the next step S6, the amount of change (ΔDH) in the refractive power obtained in step S5 corresponds to the value following the movement amount “L” of the fixation table 2A at this time (corresponding to the movement amount “L”). Is represented by diopter (D).).

When the result of the determination in step S6 is "Ye
s ", that is, while the eye to be inspected 1 follows the movement of the fixation table 2, steps S4 to S6 are repeatedly executed.
As the distance A increases, if the amount of change in the refractive power (ΔDH) of the subject's eye 1 does not follow the movement amount “L” of the fixation table 2A within one loop processing period, the result of the determination in step S6 is determined. Turns to "No" and proceeds to step S7. In step S7, it is determined whether or not the change width (ΔDH) of the refractive power at this time is equal to or less than the minimum width (0.06D).

Although the change width of the refractive power (ΔDH) is not a value following the movement amount “L”, it is still the minimum width (0.
06D) (when the determination result is “N
o ”), the movement amount“ L ”used for feedback control
Is set to L / 2 (0.5D at this time), and steps S4 to S6 are repeatedly executed.
Thereafter, steps S4 to S6 are repeatedly executed using the newly set moving amount “L”, and the change width (ΔDH) of the refractive power is changed to the moving amount “L” set at that time. When the vehicle does not follow (the determination result of step S6 is "No"), step S7 is executed again.

If the moving amount "L" at this point is not yet the minimum width (0.06D), the moving amount "L" is halved every time step S8 is executed (1.0D → 0.5D → 0.
25D->0.12D-> 0.06D: rounded up to three decimal places), and steps S4 to S6 are executed similarly. As described above, the moving amount (moving width) “L” is initially set to a large value (1.0 D), and is gradually reduced according to the change width (ΔDH) of the refractive power, so that the refractive power for far vision (DH1) is obtained. To
Accurate determination can be made in a short time.

If the movement amount "L" halved in step S8 is smaller than the minimum width (0.06D), and the subject eye 1 does not follow the movement of the minimum width (0.06D), step S8 is performed. S6 is "No", Step S7 is "Y"
es ", and proceeds to step S9.

In step S9, it is determined whether or not the moving amount "L" at this time is a positive value. At the time of the automatic measurement of the distance vision refractive power (DH1), since the movement amount “L” is a positive value, the determination result is “Yes”, and the process proceeds to step S10, where the refractive power (DH) at this time is determined. Is determined as the far vision refractive power (DH1), and this value is stored. Next, in step S11, thereafter, the near vision refractive power (DH)
In order to perform the automatic measurement of 2), the movement amount “L” is set to the initial value (−1.0D) at the time of the automatic measurement of the near-vision refractive power (DH2), and in the subsequent step S12, the fixation table 2A is set. Is replaced with the fixation table 2B, and the process returns to step S4.

In subsequent steps S4 to S8,
Automatic measurement of near vision refractive power (DH2) is performed in the same manner as automatic measurement of far vision refractive power (DH1). And
At the time of the automatic measurement of the near vision refractive power (DH2), the change width (ΔDH) of the refractive power becomes equal to or less than the minimum width (0.06D), and the subject's eye 1 moves to the minimum width (0.06D). Is not followed, step S6 is "No" and step S6
7 changes to "Yes" and the process proceeds to step S9.

At the time of the automatic measurement of the near-view refractive power (DH2), since the movement amount "L" is negative, this step S9 is performed.
Is "No", the process proceeds to step S13, and the refractive power at this time is determined as the near-view refractive power (DH2), and this value is stored. In the following step S14, the accommodation power (DC) of the eye 1 is determined based on the far vision refractive power (DH1) obtained in step S10 and the near vision refractive power (DH2) obtained in step S13. . Here, the accommodation power (DC) of the subject's eye 1 is obtained as the difference between the refractive power for far vision (DH1) and the refractive power for near vision (DH2).

In step S10, the refractive power (DH) at the time when the eye to be examined 1 does not follow the movement of the minimum width (0.06D) at the time of measuring the distance vision refractive power is calculated as the distance vision refractive power (DH1). And the eye to be examined 1
The refractive power (DH) at the time when the lens no longer follows the movement of the minimum width (0.06D) is defined as the refractive power for near vision (DH2). .06
D) The position of the fixation table 2A at the time when it no longer follows the movement of D) is determined, and the value obtained by converting the diopter value to the refractive power for far vision (DH1) is used. The position of the fixation table 2B at the time when it does not follow the movement of (0.06D) may be obtained, and this may be converted into diopter and used as the near-view refractive power (DH2) (characteristic of claim 3).

The configuration of the eye-refractive-power detecting system 10 is not limited to the illustrated example, and the present invention can be implemented by using an objective eye-refractive-power detecting device having another configuration. In the above-described embodiment, the minimum width for determining that the eye to be inspected 1 does not follow the movement of the fixation table 2 is set to 0.06D. This is because the adjustment of the glasses is performed at first. Of course, the minimum width may be set to another value.

In the above embodiment, the measurement principle of the eye-refractive-power detection system is based on the image-analysis method. However, it is needless to say that the present invention is not limited to this. Further, in the computer 31 according to the above-described embodiment, a preferred example in which the distance vision refractive power (DH1) is first determined and then the near vision refractive power (DH2) is described, but the distance vision refractive power (DH1) is described. ) Or near vision refractive power (DH2) may be determined by the measurer for each measurement.

In this case, in the flowchart shown in FIG. 4, it is determined whether or not the measurer has selected the refractive power for far vision (DH1) and the refractive power for near vision (DH2) to be measured first. Steps may be provided.

[0050]

According to the first aspect of the present invention described above,
Since both the refractive power for far vision and the refractive power for near vision are objectively determined, the accommodation power of the subject's eye can be accurately and objectively automatically measured.

According to the second aspect of the present invention, the change in the refractive power of the eye to be examined which follows the movement of the fixation table is objectively determined, and the distant distance determined based on the change in the refractive power is determined. The accommodation power of the subject's eye can be accurately obtained in a short time from the visual refractive power and the near visual refractive power. According to the third aspect of the present invention, the change in the refractive power of the eye to be examined (the change in the refractive power for far vision and the refractive power for near vision) that tries to follow the movement of the fixation table and the position of the fixation table are determined. Just by determining, the accommodation power of the subject's eye can be easily and automatically measured.

According to the fourth aspect of the present invention, the state of the subject's eye to be examined can be set to a state suitable for each of the distance vision refractive power measurement and the near vision refractive power measurement. Measurement accuracy is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an optometry apparatus 100 according to an embodiment of the present invention.

FIG. 2 is a diagram showing a first fixation table 2A for far vision refractive power measurement and a second fixation table 2B for near vision refractive power measurement.

FIG. 3 is a block diagram showing a configuration of an eye refractive power detection system 10 of the optometry apparatus 100.

FIG. 4 is a flowchart showing a measurement program executed in a computer 31.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Examinee's eye 2 Fixation table 2A 1st fixation table 2B 2nd fixation table 10 Eye refractive power detection system (eye refractive power detection means) 20 Cloud fog optical system (fixation table moving means) 30 Feedback control part 31 Computer (movement amount control means, far vision refractive power detection means, near vision refractive power detection means, accommodation power detection means) 50 imaging optical system 100 optometry device

Claims (4)

[Claims] An eye refractive power detecting means for irradiating the eye to be measured with measurement light and outputting a signal indicating the refractive power of the eye based on the reflected light; Fixation table moving means for selectively moving in a first direction moving away from the eye to be examined and a second direction approaching the eye, and a signal from the eye refractive power detecting means changing with the movement of the fixation table A movement amount control unit that determines a movement amount of the fixation table by the fixation table moving unit based on: a movement amount when the fixation table moves in the first direction by the fixation table movement unit; Distance vision refractive power detection means for obtaining a distance vision refractive power based on a signal from the eye refractive power detection means that changes due to this movement, and a fixation table moving in the second direction by the fixation table moving means. The amount of movement when the eye refractive power is changed A near-vision refractive power detecting means for obtaining near-vision refractive power based on a signal from a step, and the subject's eye based on the obtained far-vision refractive power and the obtained near-vision refractive power. An optometric apparatus comprising: an adjusting force detecting unit that obtains an adjusting force of the eye. 2. The distance vision refractive power detecting means indicates a signal from the eye refractive power detecting means with respect to a movement amount when the fixation table moves in the first direction by the fixation table moving means. When the change width of the refractive power is less than or equal to a certain value, determine the distance vision refractive power from the value of the refractive power, the near vision refractive power detection means, the fixation table moving means by the fixation table moving means, When the width of change of the refractive power indicated by the signal from the eye refractive power detecting means with respect to the amount of movement when moving in the second direction is equal to or less than a certain value, the near-view refractive power is determined from the value of the refractive power. The optometry apparatus according to claim 1, wherein: 3. The distance vision refractive power detecting means indicates a signal from the eye refractive power detecting means with respect to a moving amount when the fixation table moves in the first direction by the fixation table moving means. When the change width of the refractive power is less than or equal to a certain value, determine the distance vision refractive power from the position of the fixation table, the near vision refractive power detection means, the fixation table moving means the fixation table When the change width of the refractive power indicated by the signal from the eye refractive power detection means with respect to the amount of movement when moving in the second direction is equal to or less than a certain value, the near-field refractive power from the position of the fixation table The optometry apparatus according to claim 1, wherein: 4. The fixation table moving means, as the fixation table, a first fixation table moved in the first direction and a second fixation moved in the second direction. The optometry apparatus according to claim 1, further comprising a table.