JP2684332B2 - Subjective optometry device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a near-distance optotype presenting device arranged so as to be inserted into the visual field of a subject during a near vision test and to be removed from the visual field during a far vision test. The present invention relates to a subjective optometry apparatus.

[0002]

2. Description of the Related Art An examination for determining a spectacle lens is called an optometry, and a main part thereof is an examination of a refractive index of an eye to which spectacles should be worn, that is, a refraction examination. In the refraction test, a standard visual acuity table is usually installed at a distance of 5 m to measure distance visual acuity, but a near visual acuity table may be installed at a distance of 30 cm to measure near visual acuity. The near vision measurement is originally performed as a test for accommodation disorders and presbyopia, but if both the distance vision and the near vision are measured, new information that cannot be obtained only by the distance vision can be obtained. That is, even if the distance near-vision visual acuity is reduced, nearsightedness is expected if the nearsightedness acuity is good. Etc. are naturally expected. Further, the refraction test includes an objective test and a subjective test, and it is common to obtain a rough range by the objective test and obtain a precise visual acuity value by the subjective test. There is a method of using a refraction test table such as a visual acuity table or an astigmatism test table for the subjective refraction test, and the lens exchange method is the most commonly used method. This is 12mm in front of the eye to be examined with various optometry lenses.
, Using a standard visual acuity table placed at a viewing distance of 5 m,
This is a method of obtaining the refractive index of the eye from the power of the correction lens that obtains the maximum visual acuity.

There is also a turret type subjective optometer as a device that saves the trouble of replacing various optometry lenses on the eyeglass test rod. This is generally called a vision tester, and similar devices are sold by domestic and foreign companies. This device consists of two independent parts (for the left eye and right eye), and each part incorporates a spherical lens, a cylindrical lens, a rotating prism, a cross cylinder, an auxiliary lens, and the like. The spherical and cylindrical lenses are attached to a built-in lens turret, and rotation of them allows the lenses of various powers to be placed in front of the examinee's eyes. Now, let us consider a case where the turret type subjective optometer is used for optometry. Before performing the distance vision test and the near vision test, the examiner first sits the examiner in front of the optometer, and the spherical lens attached to the lens turret is about 12 mm in front of the eye to be examined. The relative position of the eye to be inspected is determined so as to come to the position. The distance vision test is performed by setting a standard visual acuity table at a distance of 5 m in front of the eye to be examined, allowing the examiner to see the target through the optometer, and letting the examiner answer the target. Near vision test
Similarly, in order to measure a visual acuity value at a short distance of, for example, 30 cm, a short distance visual acuity table that is composed of an optotype made for 30 cm and is hung on a member called a near point bar is used to measure a distance of 30 cm in front of the eye. This is done by allowing the subject to look through the optometer and answering the identifiable optotype.

As shown in FIG. 9, for example, a conventional near-distance visual acuity chart has one end fixed to the optotype disc 2, a housing 4 accommodating the optotype disc 2, and a top portion of the housing 4, and the other. The end of the target disc 2 is composed of a supporting rod 6 which can be attached to and detached from an optometer (not shown), and which is pivotally attached to the housing 4 by a shaft 8. The target disc 2 has its lower portion protruding downward from the bottom of the housing 4. Since the window 10 is provided on the side surface of the housing 4 that faces the optometer, by turning the lower part of the target disc 2 by hand, a desired short distance target on the target disc 2 can be selected. Objects are configured to selectively appear in the window 10. As a tendency in recent years, not only the examinee but also the examiner often performs an optometry while sitting on a chair using an electric turret type subjective optometer. But,
As long as the above near-distance acuity chart is used, when the distance vision measurement is completed and the near-distance vision measurement is performed, the examiner stands up from the chair and attaches the near-distance vision chart to the optometer and The desired near distance target must be selected and displayed by turning the plate by hand, and when the near vision measurement is completed and the far vision measurement is to be performed, the examiner stands up from the chair. There is an inconvenience that the short-range visual acuity table attached to the optometer needs to be removed from the optometer.

Further, when the short-distance visual acuity chart is used, the collimation line of the eye to be examined obliquely passes through the left-eye visual acuity measurement optical system and the right-eye visual acuity measurement optical system, and thus high-precision visual acuity measurement is performed. There was a problem that could not be done. The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to allow a tester and a test subject to sit close to each other by remote control while sitting on a chair. It is possible to switch between the visual acuity test and the distance visual acuity test, and it is possible to perform high-precision visual acuity measurement by converging the left-eye visual acuity measurement optical system and the right-eye visual acuity measurement optical system during short-distance visual acuity. An object is to provide a optometry device.

[0006]

According to the present invention, a left-eye lens unit and a right-eye lens, which incorporate a left-eye visual acuity measuring optical system and a right-eye visual acuity measuring optical system, and are axially supported by independent rotating shafts, respectively. A unit, a short-distance visual target provided on the median line of the left-eye visual acuity measurement optical system and the right-eye visual acuity measurement optical system so as to be adjustable, and a short-distance for moving the short-distance visual target on the midline. A target driving means, a lens unit convergence driving means for converging the left eye lens unit and the right eye lens unit according to the position of the short distance target on the midline, and the short distance target driving means And a lens unit convergence drive means for controlling the lens unit convergence drive means, the control means controls the lens unit convergence drive means based on the control signal of the near-distance target drive means, the near distance on the midline Target A visual acuity testing apparatus and performs congestion drive in accordance with the position. The present invention also incorporates left eye and right eye vision measurement optics,
A lens unit for the left eye and a lens unit for the right eye which are respectively supported by independent rotating shafts, and a short distance movably provided on the midline of the left eye visual acuity measurement optical system and the right eye visual acuity measurement optical system. A target, a position detecting means for a short-distance target on the midline, and a lens unit convergence for driving the left-eye lens unit and the right-eye lens unit to converge in accordance with the position of the short-distance target on the midline. A driving means and a control means for controlling the lens unit convergence driving means, and based on the detection signal of the position of the near-distance target from the position detecting means, the control means is the lens unit for the left eye and the right eye. Calculate the amount of convergence drive of the eye lens unit,
The subjective optometry apparatus is characterized in that the lens unit convergence drive means is controlled to perform convergence drive according to the position of the short-distance target on the midline. The present invention also provides a left-eye visual acuity measuring optical system and a pair of left-eye rotary prisms rotatably arranged on the optical path thereof to deviate the optical axis, and a right-eye visual acuity measuring optical system and rotation on the optical path thereof. A pair of right-eye rotary prisms that are arranged so as to deviate the optical axis, a rotary prism driving unit that causes rotation of the left-eye and right-eye rotary prisms to converge and the optical path thereof, and the left-eye visual acuity measurement optics. A short-distance target provided on the midline of the system and the right-eye visual acuity measurement optical system so as to be movable and adjustable;
The near-field target driving means for moving the near-field target on the midline, and the control means for controlling the near-field target driving means and the rotary prism driving means, the control means, The rotary prism driving means is controlled based on the control signal of the short-distance target driving means, and the rotary prism is rotated by the rotary prism driving means according to the position of the short-distance target on the midline to converge the optical axis. The subjective optometry device. The present invention further includes a left-eye visual acuity measuring optical system and a pair of left-eye rotary prisms rotatably arranged on the optical path thereof to deviate the optical axis, and a right-eye visual acuity measuring optical system and rotating on the optical path thereof. A pair of right-eye rotary prisms that are arranged so as to deviate the optical axis, a rotary prism driving unit that causes rotation of the left-eye and right-eye rotary prisms to converge and the optical path thereof, and the left-eye visual acuity measurement optics. The system and the right-eye visual acuity measurement optical system, a near-distance target provided so as to be movable on the midline, a position detecting means of the near-distance target on the midline, and a control means for controlling the rotary prism driving means. The control means calculates the amount of rotation of the left and right eye rotary prisms based on the detection signal of the position of the near-field optotype from the position detection means, and drives the rotary prism. Control means, a subjective optometric apparatus characterized by congesting the optical axis to rotate the rotary prisms above rotary prism drive means in accordance with the position of the near visual target of the midline.

[0007]

Embodiments will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the subjective optometry system includes a pair of left-eye and right-eye optometry units 130 and 130 ', a left-eye optometry unit 130, and a right-eye optometry unit 130'. Suspending housing for optometry section 180 and suspension housing for optometry section 18
The support rod 200 extends from 0 to the front, and the short-distance optotype presenting apparatus 300 supported by the support rod 200 and arranged in front of the left eye optometry unit 130. As described below,
The support rod 200 is a mechanism internally provided in the optometry part suspension housing 180, and is rotatably attached to the optometry part suspension housing 180 via a drive mechanism for rotating the support rod 200. . The near-distance optotype presenting apparatus 300 supported by the support rod 200 is, as shown in FIG. 1, at the time of the near vision test, the examination position in front of the left eye optometry unit 130 and in the direction of the line of sight of the subject. 2 and is removed from the near vision test position during the distance vision test, as shown in FIG. In FIG. 3, the drive mechanism 190 for rotating the support rod 200 is a near-field optotype presenting device setting motor 140, a main driving wheel 160 fixed to the motor 140 via a shaft 150, and the main driving wheel 160. It is composed of a driven wheel 170. The driven wheel 170 is fixed to one end of the support rod 200, and the other end of the support rod 200 is fixed to the short-distance optotype presenting apparatus 300.

The near-field optotype presenting apparatus 300 engages with the optotype housing 310, an optotype disc 330 pivotally supported by the optotype housing 310 via a shaft 320, and a peripheral edge of the optotype disc 330. A target disc rotating motor 36 for rotating the driven wheel 340 via the driven wheel 340 and the shaft 350.
0 and a target disc rotation position detection switch 370. The subjective optometry system of the embodiment includes a control circuit 400 and an operation unit 500 shown in FIG. 4 in addition to the above-mentioned components. The operation unit 500 includes a visual acuity test mode switch 5
10 and a target selection switch 520, which are respectively connected to the control circuit 40 via conductors 410 and 420.
Connected to 0. Further, the near-field optotype presenting device setting motor 140, the optotype disc rotation motor 350, and the optotype disc rotation position detection switch 360 are connected to the control circuit 400 via conductors 440, 450, and 460, respectively. ing. Further, the optometry unit 130 is connected to the control circuit 400 via the lead wire 430. Next, the operation of the above-described subjective optometry system will be described. When the visual acuity test mode switch 510 is pressed when the subjective optometry system is in the far vision test position shown in FIG. 2, a near vision test start signal is sent to the control circuit 400 via the lead wire 410. The control circuit 400 sends a control signal to the near-field optotype presenting device setting motor 140 via the lead wire 440, and the motor 140 rotates to rotate the near-field optotype presenting device 300 supported by the support rod 200, The subjective optometry system is set at the near vision test position shown in FIG.

At the same time, the control circuit 400 sends a control signal to the optometry section 130 via the lead wire 430, and the optometry section 130 is set to the near vision examination state. That is, if the subject is a person who is previously known to have, for example, -4D hyperopia by an objective or subjective test, the subject's eye should be adjusted while using the corrective lens. If this is the case, you will be able to see the 1.0 short-distance target at 0.3 m in front of you. In this case, the correction lens is a + 4D convex lens capable of correcting -4D hyperopia, and adjusts the eye closer to the subject by 3.25D from 1 / 3.25D = 0.3m. That is, the lens turret of the optometry unit 130 is rotated so that the + 4D convex lens, which is an optical member, is inserted in front of the eye as a correction lens.
Then, when the target selection switch 520 is pressed, a target disc rotation signal is sent to the control circuit 400 via the lead wire 420,
The control circuit 400 sends a control signal to the target disc rotating motor 360 via the lead wire 450, and the target disc 330 starts to rotate. When the target disc 330 is rotated to bring the desired near-distance target to the inspection position, the target disc rotation position detection switch 370 is activated to generate a rotation stop signal. This signal is sent to the control circuit 400 via the lead wire 460, and the control circuit 400 sends a control signal to the target disc rotation motor 360 via the lead wire 450 to stop the rotation of the motor 360 and to obtain the desired near-distance vision. A target is placed at the near vision inspection position. Then, the near vision test for this target is performed. Similarly, other desired near vision targets are sequentially brought to the near vision inspection position, and the near vision inspection for those targets is performed.

When performing a distance vision test for the next subject, the vision test mode switch 510 is pressed again. As a result, the reset signal is transmitted to the control circuit 4 via the lead wire 410.
Sent to 00. The control circuit 400 sends a control signal to the near-field optotype presenting device setting motor 140 via the lead wire 440, and the motor 140 rotates in the opposite direction to cause the supporting rod 20 to rotate.
The near-field optotype presenting apparatus 300, which has been set to the near-vision test position by 0, is rotated in the opposite direction to be separated from the near-vision test position, and the subjective optometry system displays the far-vision test position shown in FIG. Is set to. At the same time, the control circuit 400
Sends a reset signal to the optometry section 130 via the lead wire 430, and the optometry section 130 is set to the distance vision test state. That is, if the next subject is a person who has been previously known to have a hyperopia of, for example, -2D by an objective test or the like, the subject should use the correction lens to adjust the eyes of the subject. Before the eye 5
Have a look at the 1.0 standard index at a distance of m. The correction lens in this case is a + 2D convex lens capable of correcting -2D hyperopia, and 1 / 0.2D = 5 m in the subject's eye.
Move the adjustment closer by 0.2D. That is, the lens turret of the optometry unit 130 is rotated so that the + 2D convex lens, which is an optical member, is inserted in front of the eye as a correction lens. In this state, a distance vision test is performed on each target on the standard visual acuity table installed at a distance of 5 m. As another embodiment, the near-field optotype presenting means is placed on a supporting rod arranged along the midline of the subject, and the near-field optotype presenting means moves the above-mentioned supporting rod on the midline. An example of measuring the accommodation power of the subject by moving the short-distance visual target presentation means to the subject from a distant position to a variable predetermined position while gazing at the subject at the time of measuring the near vision is described.

In FIG. 5, the prism PRI₁And PRI
_TwoEach has a motor M₁And M_TwoAre connected,
Motor M₁And M_TwoAre connected so that the direction of rotation is reversed.
Have been. Prism PRI₁And PRI_TwoIn opposite directions
By rotating, the rotating prism PRI₁And rotation
Rhythm PRI_TwoThe direction of the line of sight that has passed through is from O △ to a predetermined △
Can be biased up to. Similarly,
Zum PRO₁And PRO_TwoEach has a motor M_ThreeAnd M
_FourIs connected to the motor M_ThreeAnd M_FourIs the direction of rotation
The wiring is reversed. Prism PRO₁And P
RO_TwoThe rotating prism is rotated by rotating the
Mu PRO₁And the rotating prism PRO_TwoThe line of sight that passed through
Direction can be deflected from OΔ to a predetermined Δ.
You. Further, pulleys P are provided at both ends of the supporting rod 200.₁And P_TwoIs the axis
It is worn and the pulley P ₁And P_TwoBelt V hangs on
Have been killed. The near-field target S is supported on the belt V.
An optotype plate T is attached. The pulley P₁To
M_FiveIs connected to the motor M_FiveAccompanying the rotation of
The optotype plate T that supports the optotype S along the support rod 200
It can be moved in both directions shown by the arrow. Above motor
M₁, M_Two, M_Three, M_FourAnd M_FiveContacts the controller 400
The control device 400 is connected to the operation unit 500.
Have been.

The operation unit 500 is provided with a target movement switch (not shown). By pressing the switch, the optotype plate T that supports the optotype S via the motor M ₅
Moves to a predetermined position on the support rod 200. At the same time, the control unit 400 calculates the angle for rotating the rotating prism based on this movement amount. By rotating the motors M ₁ and M ₂ according to the calculation result, the rotating prism PR
The rotating prisms PRO ₁ and PRO ₂ are rotated by rotating I ₁ and PRI ₂ and rotating the motors M ₃ and M ₄ . As a result, the eye E _L sees the short-distance optotype S on the optotype plate M set at a predetermined position on the support rod 200 by the line of sight extending parallel to the optical axis in the lens frame of the subjective optometer. Will be able to. In the embodiment shown in FIG. 6, the optical axis of the lens frame for the left eye and the optical axis of the lens frame for the right eye of the subjective optometer match the line of sight of the left eye E _L and the right eye, respectively. Thus, the left and right lens frames of the subjective optometer are rotated via the electric motor to perform convergence. By doing so, the eye to be inspected is adjusted by the optotype moving on the supporting rod, and the accommodation force of the eye to be inspected is measured. 6, the E _L subject's eye to the left, E _R is the right side of the eye, a VT _L and VT _R is for the left eye lens frame of the subjective-type optometric apparatus and the right-eye lens frame. Left eye lens frame VT _L
Motor M ₁ for rotating the lens frame, and the right-eye lens frame VT _R is the motor M ₂ for rotating the lens frame is connected to.

Further, pulleys P are provided at both ends of the supporting rod 200.₁as well as
P_TwoIs attached to the shaft, and the pulley P ₁And P_TwoThe bell
V is hung. The belt V has a short-distance target S.
A target plate T for supporting the is attached. In addition, the above
Car P₁Has a motor M_ThreeAre connected,
Tar M_ThreeThe target plate T that supports the target S with the rotation of
It can move along the rod 200 in both directions indicated by the arrow.
Motor M above₁, M_TwoAnd M_ThreeContacts the controller 400
The control device 400 is connected to the operation unit 500.
Have been. An optotype not shown on the operation unit 500
Dynamic switch is provided, and pressing the switch
More motor M _ThreeThe optotype plate T that supports the optotype S via
The support rod 200 is moved toward a predetermined position. Same as this
At this time, the control unit 400 determines the lens frame VT based on this movement amount.
_LAnd VT_RCalculate the angle to rotate the
I motor M₁And M_TwoDrive. This allows the lens
Frame VT_LAnd VT_RBy rotating the eye E_LAnd E_R
Each sees the target S, and each line of sight is the lens frame VT_LOptical axis of
Lens frame VT_RTo match the optical axis of.

The left side of FIG. 6 shows the left eye E _L.
And worn to a lens frame VT _L and right eye E
_It shows a state in which _R and the lens frame VTR attached thereto are adjusted to the limit distance. In this state, the left eye lens frame VT _L and the right eye lens frame VT _R of the subjective optometer.
Is in a non-rotating position. FIG. 7 shows an example in which the optotype plate that supports the optotype is manually moved. Pulleys P ₁ and P ₂ are axially attached to both ends of the support rod 200, and a belt V is hung on the pulleys P ₁ and P ₂ . An optotype plate T that supports a near distance optotype S is attached to the belt V.
Since the potentiometer-type position detection unit P is connected to the pulley P ₁ , a signal proportional to the rotation angle is generated by manually turning the potentiometer, and the signal is sent to the control unit 400. The control unit 400 is connected to a motor M that rotates the lens frame of the subjective optometer or a motor M that rotates a rotating prism housed in the lens frame of the subjective optometer. By rotating the subjective optometer P, the optotype plate is set at a predetermined position on the support rod 200. At the same time, the control unit 400 based on the control signal, the angle to rotate the lens frame VT _L and VT _R, or the rotation angle of the rotating prism housed in the lens frame is calculated, the motor M in accordance with the operation result To drive. As a result, the lens frame is rotated or the rotating prism housed in the lens frame is rotated so that the optical axis of the lens frame matches the line of sight of the eye to be inspected, or the eyes E _L and E to be inspected.
_The line of sight of the eye _R looking at the target S is made to coincide with the optical axis of the lens frame and the optical axis of the lens frame, respectively.

As a modified example, instead of the above construction, as shown in FIG. 8, a linear rack L is attached along a supporting rod 200, and a pinion (not shown) meshing with the rack L is provided with a potentiometer type. The position detector P'is connected. By fixing the optotype plate T that supports the optotype S to a member (not shown) that supports the pinion and the potentiometer P ', the optotype S is indicated by an arrow on the support rod 200 as the potentiometer P'rotates. You may comprise so that it may move to the left-right direction shown.

[0016]

Since the present invention is configured as described above, the near vision test and the far vision test are switched to each other by remote control while the examiner and the subject are both sitting in the chairs. This has the advantage that the left-eye visual acuity measurement optical system and the left-eye visual acuity measurement optical system can be converged to perform high-precision visual acuity measurement during short-distance visual acuity measurement.

[Brief description of the drawings]

FIG. 1 is a diagram showing a subjective eye examination device set at a near vision test position.

FIG. 2 is a diagram showing a subjective eye examination device set at a distance vision test position.

FIG. 3 is a perspective view showing a configuration of a subjective optometry apparatus.

FIG. 4 is a block diagram illustrating the operation of the subjective optometry system.

FIG. 5 is an explanatory diagram of an embodiment of a subjective optometry apparatus for measuring accommodative power by an optical method.

FIG. 6 is an explanatory diagram of an embodiment of a subjective optometry apparatus for measuring accommodation power by an electrical method.

FIG. 7 is an explanatory diagram of an embodiment in which the optotype presenting means is manually moved.

FIG. 8 is an explanatory view of a modification of the embodiment shown in FIG.

FIG. 9 is a perspective view of a conventional short-distance visual acuity chart device.

[Explanation of symbols]

 130 Conscious Eye Examination Means 130 'Conscious Eye Examination Means 140, 150, 160, 170 Driving Means 200 Supporting Rods 300 Short Distance Target Presenting Means 400 Control Means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Hideto, 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Topcon Co., Ltd. (56) References JP 63-135125 (JP, A) JP 62- 295639 (JP, A) Actual Kaihei 1-98601 (JP, U)

Claims (4)

(57) [Claims] 1. A left-eye lens unit and a right-eye lens unit, which incorporates a left-eye visual acuity measurement optical system and a right-eye visual acuity measurement optical system, and which are rotatably supported by independent rotation axes, respectively, and the left-eye visual acuity measurement described above. A near-distance target provided on the median line of the optical system and the right-eye visual acuity measuring optical system so as to be movable and adjustable; a near-distance target driving means for moving the near-distance target on the midline; Lens unit convergence drive means for converging the lens unit for the left eye and the lens unit for the right eye according to the position of the near-distance target on the line, and the near-distance target driving means and the lens unit convergence driving means And a control means for controlling, the control means controls the lens unit convergence drive means based on the control signal of the near-distance target driving means, and the convergence according to the position of the near-distance target on the midline. Drive Visual acuity testing apparatus and performs. 2. A left-eye lens unit and a right-eye lens unit, which incorporates a left-eye visual acuity measuring optical system and a right-eye visual acuity measuring optical system, and which are rotatably supported by independent rotating shafts, respectively, and the left-eye visual acuity measuring system. A near-distance target provided on the midline of the optical system and the right-eye visual acuity measurement optical system so as to be movable and adjustable, a position detecting means of the near-distance target on the midline, and a position of the near-distance target on the midline. A lens unit convergence drive means for convergence-driving the left-eye lens unit and the right-eye lens unit, and a control means for controlling the lens-unit convergence drive means. Based on the detection signal of the position of the target, the control means, calculates the amount of convergence drive the lens unit for the left eye and the lens unit for the right eye, controlling the lens unit convergence drive means, the median Visual acuity testing apparatus and performs congestion drive in accordance with the position of the near eye chart above. 3. A left-eye visual acuity measuring optical system and a pair of left-eye rotary prisms rotatably arranged on the optical path thereof to deviate the optical axis, and a right-eye visual acuity measuring optical system and rotating on the optical path thereof. A pair of right-eye rotary prisms that are arranged so as to deviate the optical axis, a rotary prism driving unit that interlocks the rotations of the left and right-eye rotary prisms to converge the optical path, and the left-eye visual acuity measurement optical system System and a right-eye visual acuity measuring optical system, a near-distance target provided so as to be movable and adjustable on the midline, a near-distance target driving means for moving the near-distance target on the midline, and the near-distance target Control means for controlling the optotype driving means and the rotary prism driving means, wherein the control means controls the rotary prism driving means on the basis of a control signal from the near-distance optotype driving means. Visual acuity testing apparatus characterized by congesting the optical axis to rotate the rotary prisms above rotary prism drive means in accordance with the position of the near visual target midline. 4. A left-eye visual acuity measuring optical system and a pair of left-eye rotary prisms rotatably arranged on the optical path thereof for deviating the optical axis, and a right-eye visual acuity measuring optical system and rotating on the optical path thereof. A pair of right-eye rotary prisms that are arranged so as to deviate the optical axis, a rotary prism driving unit that interlocks the rotations of the left and right-eye rotary prisms to converge the optical path, and the left-eye visual acuity measurement optical system The system and the right-eye visual acuity measurement optical system are provided with a near-distance target movably provided on the midline, a position detecting unit for the near-distance target on the midline, and a control unit for controlling the rotary prism driving unit. The control means calculates the amount of rotation of the left and right eye rotary prisms based on the detection signal of the position of the near-field optotype from the position detection means, and the rotary prism drive. Control means, subjective optometric apparatus characterized by congesting the optical axis to rotate the rotary prisms above rotary prism drive means in accordance with the position of the near visual target of the midline.