COLOUR COORDINATES ANALYSIS OF COLOUR-BLIND CORRECTIVE ILLUMINATIONS BY USING PANEL D-15 AND ISHIHARA TESTS

摘要

The Farnsworth panel D-15 test and the Ishihara test are the most widely used screening test for colour vision deficiency. Tamura et al. (CRA, 40, 218-223, 2015) found that light-emitting diodes (LEDs) of a particular colour improved the identification of numbers in the Ishihara test and reduced the incorrect selection of D-15 colour caps by observers with deuteranopia (generally called red-green colour blindness). However, the theory of why LEDs of a particular colour improved the visual performances of observers with deuteranopia in colour vision tests had not been analysed sufficiently. This study describes the results of a theoretical colour coordinates analysis of D-15 and Ishihara tests that use a simulated D65 light and three types of colour-blind corrective LED illuminations proposed by Tamura et al. In addition, this study examines our proposed quasi-uniform colour space and illustrates why Tamura's LED illuminations improved the visual performances of observers with deuteranopia.