COMPUTER-BASED ASSESSMENT OF RED GREEN CO LOR-VISION DEFICIENCIES/

A commonly used method of investigating colour vision, that is, the ab ility of the human visual system to discriminate colours, is based on the use of isochromatic colour plates, such as those used in the Ishih ara test. The present paper describes a new computer-based method of d etermining red/green colour vision deficiencies. The method involves t he presentation of Ishihara colour plates on a computer monitor. It ha s been verified experimentally that, despite the differences between t he spectral emission of the computer screen and the daylight reflected by the Iskihara plates, the method is capable of distinguishing betwe en subjects with from those without colour vision deficiencies. For sc reening purposes. the use of a reduced number of plates is suggested. This suggestion makes use of nine instead of 14 plates, and the criter ion of two incorrectly recognized plates to determine a colour vision deficiency.