PURPOSE: To realize automization of a test of visual acuity by displaying indexes of at least three kinds of visual acuity values on a liquid crystal display board as a Landolt ring pattern, and allowing a display of a Landolt ring to be subjected to program control so that presentation sequence of the indexes is changed in accordance with an examinee's answer.

CONSTITUTION: In this visual acuity testing instrument main body, a Landolt ring for a testing distance 5m, that is, a liquid crystal display board 2 on which three kinds of Landolt rings 3-5 whose visual acuity values are 1.0, 0.7 and 0.3, respectively is provided. In each Landolt ring 3-5, gaps in four directions of up-down and left-right are constituted as different liquid crystal elements, therefore, the Landolt rings in four directions can be displayed. Also, in four corners of the liquid crystal display board 2, result display parts A-D for displaying a result of measurement by four steps of ≥1.0 visual acuity, 0.7 visual acuity, 0.3 visual acuity, and ≤0.3 visual acuity are provided. The result display parts A-D are subjected to turn-on control in accordance with the visual acuity decided, based on whether an examinee's answer is correct or erroneous.