Visual Thresholds in the Deutan Type of Red-Green Deficient Colour Vision

Abstract

Defective temporal integration for a foveally fixated 100’ of arc red (660 nm) Btest flash presented on a 30 cd/m² yellow (Schott, OG 530) background was measured in subjects with deuteranopia, as well as in subjects with anomalous trichromacy of the deutan type. The mean integration time was 77 ± 17 ms in 12 normal subjects but only 35 ± 6,46 ± 11 Band 41 ± 15 ms in respectively 6 subjects with deuteranopia, 7 with extreme deuteranomaly Band 9 with deuteranomaly. An increase in the test duration from 10 to 200 ms increased the mean relative sensitivity by 0.85 ± 13 log units in the normal subjects compared with 0.45 ± 0.05, 0.57 ± 12 and 0.56 ± 19 in subjects with deuteranopia, extreme deuteranomaly and deuteranomaly.