| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a visual acuity tester which makes an exact test possible without depending upon a test distance. <P>SOLUTION: The visual acuity tester of a projection type for projecting an optotype for visual acuity test to a screen placed in a distant position is provided with an optotype projection optical system capable of changing the imaging position of the optotype according to the installation distance to the screen and light controllable means for adjusting the projection light quantity of the optotype with respect to a change in the imaging position of the optotype. <P>COPYRIGHT: (C)2004,JPO |
