On the need for spatial component in describing colour vision deficiency

Abstract

Colour vision deficiency (CVD) is traditionally described using colorimetric models that treat colour perception as a pointwise phenomenon. While this approach has been essential for defining diagnostic methods and colour vision simulators, it does not account for the spatial mechanisms through which the visual system interprets colour. These mechanisms, acting mainly at cortical levels, play a central role in how colours are perceived. However, studies investigating their role in colour-deficient observers are still limited and fragmented. This paper reviews and discusses research that introduces spatial processing into the study of CVD. The results consistently show that small contextual variations can significantly affect colour discrimination in colour-deficient observers. We argue that colour vision, both normal and deficient, cannot be fully described through pointwise colorimetric principles alone. To achieve a realistic understanding of colour perception, diagnostic tools and simulators must include the spatial mechanism of vision.

Keywords: colour deficiency, colour blindness, colour in context, spatial processing in vision