COLOUR VISION THEORIES

Reflections on abnormal colour vision and theories of colour.

Historically, physiology is the daughter of pathology. Healthy people struggling with an overwhelming nature had no time to bother with the workings of their organs, and doctors-naturallywere always preoccupied with disease. For them the argument from malfunction to normal function has become almost second nature and the successes of this approach in such fields as neurology, endocrinology, and...

Colour-Vision and Colour-Blindness

Colour vision

The immense range of colours that we see belies the relative simplicity of the system underlying colour vision. We see colours because each of the three distinct types of cone photoreceptor in our retinae is sensitive to a different range of wavelengths of light. The L, M and S cones, colloquially called red (R), green (G), and blue (B), are selective for long, middle and short wavelengths, res...

Colour vision

Editorial Colour vision 2006 is an important bicentenary for the Ulster Medical Society. In 806, the Belfast Medical Society was founded and the later formation of the Belfast Clinical and Pathological Society in 853, allowed amalgamation of both societies to form the current Ulster Medical Society in 862. The vision of the early founders of the Belfast Medical Society, was far sighted, and som...

Colour vision: Is colour constancy real?

Colour constancy is typically weaker in the laboratory than it seems in our everyday experience. New measurements using real-world stimuli show that colour constancy is in fact almost perfect, and that several different perceptual mechanisms contribute to achieving it.