JPH0624506B2 - Visual acuity test equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a visual acuity test apparatus suitable for use in an ophthalmology clinic or the like.

[Prior Art] Conventionally, in a visual acuity test apparatus that sequentially presents liquid crystal optotype patterns, in order to make the optotype patterns used for inspection clear,
The target pattern to be inspected next is presented after or at the same time when the target pattern that has been examined is erased. However, in this method, when a new target pattern is presented, the target target pattern disappears,
There is a drawback that the adjustment of the focus of the eye tends to be unstable.

[Object of the Invention] An object of the present invention is to provide a time for presenting two patterns together when switching the presentation of the liquid crystal optotype pattern, so that the eye acuity that assists the eye adjustment and enables a stable visual acuity test. To provide an inspection device.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to present a target pattern presenting means having a plurality of target patterns and the target patterns individually for displaying the target pattern. A visual acuity test apparatus comprising: a control means for temporarily presenting an eye adjustment pattern together with an optotype pattern to be displayed next when switching.

Embodiments of the Invention The present invention will be described in detail based on the illustrated embodiments.

In FIG. 1, S is an eye to be inspected, and a liquid crystal target pattern composed of a plurality of Landolt rings, for example, is formed on the liquid crystal plate 1 for displaying the test target pattern. When the optotype pattern to be presented is designated from the optotype presentation input unit 2, the optotype pattern is presented on the liquid crystal plate 1 via the liquid crystal display control means 3. Target presentation input unit 2
Is controlled by the input from the examiner or the output from the microprocessor, and input is performed from the optotype presenting input unit 2 so that the optotype patterns are sequentially presented until the visual acuity test is completed.

2 to 4 are front views for explaining the operation of the liquid crystal plate 1. Liquid crystal optotype patterns P1 to P6 of different sizes are provided on the liquid crystal plate 1, and the inspection is shifted to the state of FIG. 2 → FIG. 3 → FIG. That is, FIG. 2 shows a state in which the optotype pattern P2 is being inspected, and FIG. 3 shows a state in which the inspection of the optotype pattern P2 ends and the process shifts to the inspection of the optotype pattern P4. Target pattern by 3
It is controlled so that both P2 and P4 are presented. As shown in FIG. 3, the target patterns P2 and P4 before and after the presentation is switched
By providing a time for presenting both the target and the target, the subject does not lose sight of the target for adjusting the focus, and it becomes unnecessary to adjust the focus each time the presentation of the target pattern is switched. Incidentally, the optimal time for presenting these two optotype patterns P2 and P4 is about 0.1 to 0.2 seconds. Further, FIG. 4 shows a state in which the inspection is performed using the optotype pattern P4 through FIG.

In the embodiment, the eye adjustment pattern used is the optotype pattern previously displayed, but it is needless to say that it may be an independent pattern separate from the optotype pattern. Further, when the optotype pattern is switched, the independent eye adjustment pattern may be temporarily displayed together with the previously displayed optotype pattern before being displayed together with the optotype pattern to be displayed next.

[Effects of the Invention] As described above, the visual acuity testing apparatus according to the present invention provides the time for presenting two patterns together when switching the presentation, so that the eye adjustment when the subject performs the visual acuity test. It makes it possible to perform a stable visual acuity test.

[Brief description of drawings]

The drawings show one embodiment of the visual acuity test apparatus according to the present invention. FIG. 1 is a layout view thereof, and FIGS. 2 to 4 are front views of a liquid crystal plate. Reference numeral 1 is a liquid crystal plate, 2 is an optotype presenting input unit, 3 is liquid crystal display control means, and P1 to P6 are liquid crystal optotype patterns.

Claims (3)

[Claims] 1. An optotype presenting means having a plurality of optotype patterns, and an optotype which individually displays the optotype patterns and next displays an eye adjustment pattern when the presentation of the optotype patterns is switched. A visual acuity test device comprising: a control unit that presents the pattern together with the pattern. 2. The visual acuity test apparatus according to claim 1, wherein the eye adjustment pattern also serves as a previously displayed optotype pattern. 3. The visual acuity test apparatus according to claim 1, wherein the optotype pattern is made of liquid crystal.