[A new test (C-test) for quantitative examination of crowding with test results in amblyopic and ametropic patients (author's transl)].

A new acuity test was developed with a defined space between symbols to determine the effect of crowding on visual line acuity. Landolt-C was used as a symbol and the space between symbols (either 2 to 3 min. of arc or 17 to 18 min. of arc) was kept constant for all acuity values. The test permits a quantitative examination of crowding phenomena. The experimental results obtained in measurements of visual line acuity in normal-sighted, amblyopic and ametropic subjects are presented. The results of treatment for amblyopia had evidently been interpreted too optimistically in many patients hitherto.