JPH0120614B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an astigmatic eye testing device, and in particular, a group of parallel lines with different inclination angles are used instead of a group of radiation in a conventional astigmatic eye visual acuity test optotype. A plurality of astigmatism targets are arranged on almost the same circumference, and by rotating them, the visibility is increased, making it easier to identify the examinee, and making it possible to accurately measure the angular axis and astigmatism power. The present invention relates to an astigmatism eye testing device.

(Prior art) Conventional optotypes for visual acuity tests for astigmatic eyes caused by curvature of the cornea or crystalline lens have been 12 clock-shaped optotypes as shown in Figure 5, or as shown in Figure 6. 36
Astigmatism markers made of thin radial lines from books were used. In the figure, 0~180℃ represents the angle axis,
21 is a radial line.

In addition, as an astigmatism target, only the upper half of Fig. 6 was used, that is, one composed of 18 radial lines or subdivided into 72 radial lines.

(Problems to be Solved by the Invention) However, with the apparatus having the above configuration, it is extremely difficult to distinguish between subjects using the 12 clock-shaped visual targets provided every 30 degrees as shown in FIG. , in a device using 36 (or 18, 72, etc.) thin radial wires as shown in Figure 6, for example, the axis is 90° (+)
As shown in Figure 7, subjects with astigmatism and (-) astigmatism with an axis of 180° can see relatively clearly at 90°, but as it approaches 0° and 180°, It is extremely difficult to accurately determine that, for example, (+) 125° is the true astigmatism angle, because the blur increases as the angle increases, and 90° appears to be the best and 180° is the worst. However, there was a problem that the measurement results were uncertain.

This invention eliminates the problems of the prior art, makes it easy for patients and children with poor eyesight to discern, and enables infinitely accurate angular axis measurement by rotating the astigmatism target. The object of the present invention is to provide an astigmatism eye testing device.

(Means for Solving the Problems) The configuration of the present invention for achieving the above object will be explained using FIGS. 1 and 2 corresponding to the embodiments.
The present invention provides an astigmatism eye testing device that includes a group of lines 13 arranged at equal intervals and in parallel, the centers of which are approximately on the same circumference, and the inclination angle of the group of lines 13 increases by 30°. circular 6 arranged to go
The optotype groups 12-1 to 12-6 have the optotype numbers 12-1 to 12-6 inside the optotype groups 12-1 to 12-6.
6 is displayed, and a green (+) astigmatic axis indicator mark 14 is displayed on the outside of the optotype 12-3, and an opposing red mark is displayed between the optotypes 12-1 and 12-2 and between 12-4 and 12-5. a circular optotype board 12 having a (-) astigmatic axis indicating mark; and the astigmatism target group 12-1, which rotatably supports this optotype board 12 and is disposed opposite to the outer periphery of the optotype board 12. A fixed protractor 11 that has a scale 11a that displays the astigmatic axis power of ~12-6 and green letters 1 to 6 of the optotype numbers every 30 degrees on the outer circumference of the scale 11a.
It is equipped with the following.

(Function) According to the present invention, since the astigmatism eye testing device is configured as described above, several groups of thick lines are formed at the same angle.
6 optotypes 12-1 to 12 arranged at equal intervals
-6 was divided and arranged every 30° on a 360° circumference, so
If the striae group of the 90° optotype can be clearly seen, the black line of the 180° optotype on the opposite side will blur and bleed into the white line, and the white line will bleed into the black line, resulting in an overall gray color and poor visual acuity. It has become easier for weak patients and children to determine which of the six visual targets is the best and which is the worst.

Also, the angle is increased in 30° increments, which is the easiest to distinguish.
By rotating this optotype disk, it became possible to measure the angular axis with infinite precision.

Therefore, the above-mentioned problems can be eliminated.

(Example) The present invention will be explained in detail below using the drawings.

FIG. 1 is an overall view showing an embodiment of an astigmatism marker according to the present invention. In the figure, numeral 11 is a fixed protractor, and on the ring-shaped outer periphery there is an optotype, which will be described later, shown in green. Numbers 1 to 6 corresponding to the number are displayed, and number 6
The reason why there are two is that the prescription will be the same no matter which way you turn it, and inside these there is a number 1.
The numbers 0 to 180° representing the angular axis correspond to ~6.
It is displayed in uppercase letters every 30 degrees, in lowercase letters every 10 degrees, and in small scales every 5 degrees. Also, 12 is an optotype board, 12
-n (n = 1 to 6) For example, 12-1 is one of the astigmatism markers, in which seven black lines 13 are arranged in parallel at equal intervals in a circle and are inclined at an angle of 30 degrees with respect to the horizontal direction. Similarly, 12-3 is a 90° target having an inclination of 90° with respect to the horizontal direction. In this way, the optotype plate 12 is set at 0°, 30°, 60°,
Six optotypes are arranged at 30° angles such as 90°, 120°, and 150° so that their centers are approximately hexagonal, and the inner circumference of this optotype group 12-n optotype numbers 1 to 6 are marked on the optotype board 12, and a green astigmatism axis indicating mark 14 (hereinafter referred to as the green triangle mark) is provided on the outer periphery of the optotype board 12 above the third optotype 12-3. , a red indicator mark 15 (hereinafter referred to as a red triangle mark) is attached between each of the first, second, fourth, and fifth optotypes. And the circular optotype board 12 has a fixed degree of 1
It is rotatably supported so as to face the scale part 11a of No. 1.

When an astigmatic person looks at the astigmatism target constructed as described above, for example, as shown in Figure 2, if the third optotype (90°) is seen most clearly, then the sixth optotype (180°) In the striation group 13, the black line is blurred and bleeds into the white line,
In addition, since the white line bleeds into the black line, the entire line appears gray, and can be clearly distinguished even by patients and children with poor eyesight. Figure 2 shows direct astigmatism.
Of the oblique astigmatism and oblique astigmatism, this shows the appearance of straight astigmatism.

Similarly, it can be determined that if the first visual target (30°) is the best, the fourth visual target (120°) on the opposite side is the worst.

Next, how to use this astigmatism target will be explained.

(1) First, move the green triangular mark 14 above the third optotype 12-3 of the optotype board 12 to the scale part 11a of the protractor board 11.
(See Figure 2).

(2) Next, the eyes are examined for each eye on the left and right, and the examinee
Astigmatism is assumed to be absent if all of the 6th optotypes provide clear vision in the same way (see Figure 1).

(3) If there are bright and dark areas in the first to sixth optotype groups, ask the subject to select the optotype number that is most clearly visible.

(4) If the answer is that the fourth optotype is the clearest as shown in FIG.
Align it with the green letter 4 above.

(5) Therefore, since the third optotype is now the clearest, the next question is which of the second and fourth optotypes is more visible. If the answer is that the 4th visual target looks better, then the green triangle mark 1
4. Turn the optotype board 12 by 10 degrees clockwise, that is, toward the fourth optotype.

This time, if the answer is that the second optotype is sharper than the fourth optotype, move back 5 degrees toward the second optotype. Now, if the third optotype is the best and the second and fourth optotypes have the same density, then the 125° pointed by the green triangular mark 14 is the axis of (+) astigmatism, and the red triangular mark The 35° point indicated by 15 is the axis of (-) astigmatism (see Figure 4).

(6) And if it is (+) astigmatism, the axis is 125°,
(-) If you have astigmatism, if you give astigmatic lenses starting from the weakest one with 35 degrees as the axis, if you can see clearly in the 3rd and 6th optotypes when you give a 1.00 lens, then
Since the axis and power are appropriate, the entire optotype group appears evenly (see Figure 1).

Here, if a lens of 1.25, which is one step stronger than 1.00, is provided, the sixth optotype will appear darker than the third optotype, making it possible to avoid the worst over-adjustment that is most likely to cause errors in conventional optotypes.

(7) In the case of irregular astigmatism, among optotypes 1 to 6, for example, optotypes 3 and 5 are the sharpest, and the other optotypes are blurred in different sizes, resulting in completely disordered and incorrect astigmatism. Because it looks like this, it is easy to identify irregular astigmatism. Since this cannot be corrected with glasses, by using contact lenses that adhere closely to the cornea, tears can penetrate into the irregular gap between the lens and the cornea and become integrated with the lens, correcting irregular astigmatism. .

Incidentally, in the above embodiment, each optotype provided on the optotype board 12 was provided within the same circular frame, but this shape may be triangular, square, diamond, or other shapes. The number of optotypes provided on the optotype board 12 is most preferably six as in this embodiment, but this number may be increased or decreased.

Furthermore, although the astigmatism target according to the present invention may be used alone, it goes without saying that it may also be used as part of an eye refractive error testing device for myopia, hyperopia, and the like.

(Effects of the Invention) As explained in detail above, according to the present invention, the inclination angles of several groups of thick lines are adjusted in parallel and at equal intervals.
Six optotypes that increase in 30° increments are arranged in a disc over 360°, so if the optotype consisting of a group of striae with an inclination angle of 90° can be clearly seen, the opposing 180° optotype is a striae. The black line of the group blurs and bleeds into the white line,
In addition, the white line, on the contrary, appears to bleed into the black line, making the entire area gray, and the shading between the 90° and 180° optotypes can now be clearly distinguished, compared to the conventional thin and large numbers. Compared to optotypes consisting of radial lines, it is easier to distinguish even for patients and children with poor eyesight. In addition, since the conventional optotype divided 360° into two upper and lower parts at 180°, the use of the 360° surface was essentially 1/2, but with the present invention, the inclination angle differs by 30°. By dividing and arranging six optotypes on a 360° circumference, we were able to obtain effects such as doubling the surface area.

[Brief explanation of drawings]

FIG. 1 is an overall view showing an embodiment of the astigmatism eye testing device according to the present invention, FIG. 2 is a view showing how a subject looks with respect to an astigmatism target, and FIG. 3 is a diagram showing one state of use of the present invention. Fig. 4 is a state diagram in which the astigmatism axis angle is determined, Fig. 5 is an overall diagram showing an example of the configuration of a conventional astigmatism target, and Fig. 6 is a state diagram in which the astigmatism axis angle is determined.
The figure is an overall view showing another example of the configuration of a conventional astigmatism target.
FIG. 6 is a diagram showing an example of how an astigmatic person sees in the conventional example. DESCRIPTION OF SYMBOLS 11... Protractor board, 11a... Scale part, 12... Optotype board, 12-1 to 12-6... Optotype, 13... Line group,
14...Green triangle mark, 15...Red triangle mark.

Claims (1)

[Claims] 1 Consisting of a group of lines arranged in parallel at equal intervals, the centers of which are arranged on approximately the same circumference,
It has a plurality of optotype groups of the same shape arranged so that the inclination angle of the striae group increases by a constant angle, and the optotype number is displayed inside this optotype group, and A circular optotype board having a (+) astigmatism axis indication mark and an opposing (-) astigmatism axis indicator mark on the outside; this optotype board is rotatably supported, and the optotype board is supported on the outer periphery of the optotype board. An astigmatic eye testing device comprising: a fixed protractor having a scale for displaying the astigmatic axis power and optotype number of the optotype group.