JPS61206423A - Visual field measuring apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a visual field measurement device used for diagnosing eye diseases, cranial nerve diseases, and the like.

[Prior art] The range that can be seen when the palm is facing in two fixed directions is called the visual field, and this visual field test is used not only to check for eye diseases, but also for example diabetes and brain abnormalities. This is an important test that is essential for identifying a wide range of illnesses and illnesses. Conventionally, this type of device projects an optotype inside a hemispherical dome placed in front of the subject's eye, and the optotype is observed from the front of the hemispherical dome with one eye at a time. Since measurements are taken with an eye shield such as an eye patch attached to the non-measuring eye of both eyes, it takes considerable effort to change and replace the eye shield4, and the test subject has to cover one eye. There is a problem in that patients have to undergo examinations in the unnatural state of peeling.

[Object of the Invention] In order to improve the above-mentioned problem, the object of the present invention is to provide the main unit presenting means with a left/right eye selection function,
This visual field measurement device eliminates the need for the conventional eye shields, saves the trouble of replacing and replacing eye shields, and allows the examinee to take the test in a natural state with both eyes open. It is about providing.

[Summary of the invention] The gist of the present invention is to achieve the above objects.

As a parent device presentation means that presents an optotype toward the eye being examined.

The visual field measuring device is characterized in that it includes a left/right switching means for switching the index corresponding to the left eye and right eye of the eye to be examined.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 shows a first embodiment of the present invention, and shows an EL
, ER indicate the left eye and right eye of the subject's eye, respectively.

A common translucent plate 1 is arranged in front of these eyes EL and EH, and a focusing lens 2. A target projection optical system M including an index 3 and an illumination light source 4 is arranged.

In FIG. 1, the optical axis of the optotype projection optical system M is on the spatial axis passing through the center of the iris of the left eye EL, and the left eye EL is in a state of being measured. The light from the index 3 illuminated by the illumination light source 4 passes through the focusing lens 2 and the semi-transparent plate 1 to once form an aerial image A, and then reaches the left eye EL and forms an image on the fundus of the eye. The optical axis of this optotype projection optical system M can be freely rotated in space around the iris of the left eye EL.

Further, the focusing lens 2 is movable on the optical axis, and its position is determined by the refractive power of the eye EL to be examined.

To switch the eye to be examined from left eye EL to right eye ER, first
All you need to do is move the optotype projection optical system M shown in the figure from the spatial axis to the spatial axis R passing through the center of the iris of the right eye EH, as shown by the arrow.
The semi-transparent plate 1 is for preventing the subject's eye from seeing the movement of the optotype projection optical system M in space.

FIG. 2 shows a second embodiment of the present invention, in which an illumination light source 5 illuminates an index 6, and a projection lens 7 focuses the light from the index 6 onto a hemispherical dome 8. The index image B on the hemispherical dome 8 is observed with the left eye EL or the right eye ER via liquid crystal shutters 9L and 9R.

In this case, independent measurements of left eye EL and right eye ER can be performed by separately selecting light blocking and light transmission with the liquid crystal shutter 9L or 9R placed in front of left eye EL or right eye ER. Can be done.

FIG. 3 further shows a third embodiment, in which light from an index 12 illuminated by an illumination light source 11 is formed into a -H aerial image C by a focusing lens 13, and then reflected by an elliptical dome 14. The iris Ep of the eye E to be examined
It is designed to focus on the fundus of the eye through the lens.

The elliptical dome 14 is arranged with its first focus aligned with the iris Ep of the subject's eye E, and the optotype projection light flux is directed to the elliptical dome 14.
It passes through the second focal point F of. In order to change the position of the optotype on the fundus of the eye E to be examined, the optical axis S of the optotype projection optical system can be freely rotated in space around the second focal point F to adjust the angle of view. Furthermore, in order to match the diopter of the eye E to be examined, the focusing lens 13 may be moved on the optical axis.

In this embodiment, for example, when switching from the right eye ER to the left eye KL, the elliptical dome 14 as shown in FIG.
, and bring its first focal position from the position of the iris PR of the right eye to the position of the iris PL of the left eye, the optical axis S of the optotype projection optical system changes to the position indicated by the dotted line Sa. , left eye EL
It becomes possible to measure the visual field.

[Effects of the Invention] As explained above, the visual field measurement device according to the present invention includes a left/right switching means in the parent unit presenting means, and selectively switches according to the left eye or right eye of the eye to be examined. Visual field measurements for both the left and right eyes can be performed efficiently without using conventional eye shields, and the test subject can open both eyes very naturally without having one eye blocked. Another advantage is that the test can be taken in a safe condition.

[Brief explanation of the drawing]

The drawings show examples of the visual field measuring device according to the present invention, and FIG. 1 is an optical layout diagram of the first embodiment, FIG. 2 is an optical layout diagram of the second embodiment, and @3 diagram is an optical layout diagram of the second embodiment. FIG. 4 is an optical layout diagram of the third embodiment, and an explanatory diagram of the action of the movement of the elliptical dome of the third embodiment. Symbol l is a semi-transparent plate, 2 is a focusing lens, 3.6
．． 12 is an optotype, 4.5.11 is an illumination light source, 7 is a projection lens, 8 is a hemispherical dome, 9L and 9R are liquid crystal shutters,
13 is a focusing lens, and 14 is an elliptical dome. Patent applicant Canon Co., Ltd. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. The optotype presenting means for presenting an optotype toward the eye to be examined is provided with a left-right switching means for switching the indicator corresponding to the left eye and right eye of the eye to be examined. Visual field measuring device. 2. The visual field measuring device according to claim 1, wherein the left/right switching means is a means for mechanically moving the master unit presentation means. 3. The visual field measurement device according to claim 1, wherein the left/right switching means is a light shielding means that can select between light shielding and light transmission. 4. The visual field measuring device according to claim 1, wherein the optotype presentation means includes an elliptical dome, and the left/right switching means is means for moving the elliptical dome. 5. The visual field measuring device according to claim 1, wherein the optotype presentation means includes focus adjustment and field angle adjustment means.