Coloured filters will not give red-green colour deficient observers normal colour vision

Abstract

There have been several reports over the last 200 years on how coloured filters might improve red-green colour deficient observers’ ability to discriminate colours. Many red-green colour deficient observers have unrealistic expectations with regards to the effect of such filters after reading some of these accounts. This case report presents the accounts of three young men with red-green colour-deficiency who share an ambition to study for a profession that require normal trichromatic colour vision: shipmaster, chief officer and aircraft technician. ChromaGen filters were fitted monocularly and the three men were tested with a range of colour-vision tests. All three were classified as having a deutan colour-vision deficiency. The results from colour-vision testing with and without filters are discussed in relation to functional improvement and also in relation to ethical issues.

Suprathreshold contrast response in normal and anomalous trichromats

“…It has previously been suggested that the loss of chromatic signal in anomalous trichromats due to reduced separation of the cone spectral sensitivities might be ameliorated by the use of selective filters that would act to increase their spectral separation [46,47]. The MLDS paradigm for measuring contrast appearance would be an ideal paradigm for studying the long-term effects of such aids on contrast perception.…”