JPH07222717A - Objective automatic measuring instrument for eye position by light reflection on cornea - Google Patents

Abstract

PURPOSE:To accurately perform measurement under reducing a measuring error, by observing the movement and rotation of an instrument by expanding light reflection on the cornea of a testee body on a monitor television set. CONSTITUTION:Two instruments respectively for right eye and left eye are provided symmetrically. The center of the pupil of an eyeball 3 to receive a test is adjusted so as to coincide with the center of the reception plate 8 of a video camera by moving a main body in all directions. At this time, the light reflection on the cornea is observed on the monitor television set by expanding with the video camera. Also, the light reflection on the cornea is adjusted so as to be located in the center of an image by rotating the main body. The position of the main body at that time is read, and it is converted to the position of the eyeball. In other words, this instrument observes the light reflection on the cornea by expanding on the monitor television set. Also, since no hindrance by a lens barrel, etc., occurs compared with the case that the cornea is directly observed, the cornea can be observed from the front. Therefore, measuring accuracy can easily be improved.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is a medical instrument for measuring eye position.

[0002]

2. Description of the Related Art Conventionally, as a method of measuring the eye position necessary for diagnosing strabismus, there is a method using a normal cut scalar, a prism bar or the like. In these methods, the eye is moved by manually moving the target, and the position of the target when the light reflection on the cornea by the light source reaches the center of the pupil is measured. In addition, the measurer manually moves the target to measure the position of light reflection on the cornea with the naked eye. For the above reasons, these measuring methods are disadvantageous in that they are inaccurate due to the subjectivity of the measurer and that the measurement takes time.

[0003]

In the conventional measuring method, the measurer manually moves the target to measure the position of light reflection on the cornea with the naked eye. Therefore, these measuring methods are disadvantageous in that the subjectivity of the measurer is inaccurate and the measurement takes time. The present invention solves this drawback.

[0004]

The device is placed symmetrically for the right and left eyes. The main body is moved vertically and horizontally so that the center of the pupil of the eyeball (3) to be inspected is located at the center of the image of the video camera. The magnifying observation with the video camera increases the accuracy. Also, by rotating the main body, the light reflection on the cornea is adjusted so as to come to the center of the image. The position of the main body at this time is read and converted into the position of the eyeball.

[0005]

[Operation] Two of these devices are installed symmetrically on the desk by the columns. At that time, the column is allowed to move up and down and rotate. The main body rotates with respect to the column. All of these movements can be read on the scale of movement. The eyeball to be examined is magnified by a video camera and displayed on a monitor TV. On the screen of this monitor TV, the main body is moved so that light is reflected in the center of the pupil, the scale at this time is read, and the position of the eyeball is determined.

[0006]

EXAMPLE The device is used for strabismus patients. First, the fixation target is gazed at at the target, and the main body is moved so that light reflection is reflected in the center of the pupil of the squint eye. The amount of movement at this time is read and used as the perspective angle.

[0007]

The present device magnifies and observes light reflection on the cornea on a monitor television. In addition, there is no obstruction to the lens barrel, etc., as compared to a platform for directly observing the cornea. Therefore, the cornea can be observed from the front. Due to the above two points, it is an effect of the present invention that the measurement system is improved.

[Brief description of drawings]

FIG. 1 Optical path diagram of this device

[Explanation of symbols]

(1) is an electric light that illuminates the target (2) is the target (3) is the eyeball to be examined (4) is a lens A for canceling the adjustment A (5) is a mirror (6) for changing the optical path The half mirror B (7) for changing the optical path is a lens B (8) for forming an image on the image receiving plate of the video camera, and the lens B (8) is an image receiving plate of the video camera.

Claims (1)

[Claims] 1. The movement and rotation of the device moves the optical system in the horizontal and vertical directions about the turning point of the eyeball,
The optical axis of the device and the eye axis are matched. At this time, a video camera is used to clearly detect the position of the light reflection.