| 摘要 |
PROBLEM TO BE SOLVED: To measure a visual acuity, visual field or sensitivity of a retina with the same device. SOLUTION: A target on a liquid crystal plate 4 appears as infinitely far for an examinee. A target mark M such as a Landolt ring with a variety of size and four directions or the like is displayed one after another on the liquid crystal plate 4 when measuring the visual acuity. The examinee answers the direction of the visual index mark M displayed on the liquid crystal plate 4. When a controller recognizes it, he turns off the light source 7 other than an LED light source 7 in its direction, and displays to the examinees the direction which is about to be inputted. Various visual indexes M are shown one after another according to the program, and the controller judges true-false of the answer, and automatically measures the visual acuity. |
