SELECTIVE SPARING OF COLOUR VISION

The expression selective sparing of colour vision refers to a rare syndrome in which the affected individual is blind, except for the conscious perception of colour. The condition was first described in 1933 by the American neurologist Israel Spanier Wechsler (1886-1962) in relation to an individual who had suffered from carbon monoxide poisoning. After having been unconscious for 2 h due to a house fire, the man turned out to be virtually blind. However, his colour vision was so well preserved that he was able to distinguish colours and even shades of colours. As Wechsler concludes, "The case herein presented warrants the statement that color vision and visual acuity can be dissociated in such a way that the former is preserved while the latter is impaired." Conceptually as well as phenomeno-logically, selective sparing of colour vision constitutes the counterpart of * achromatopsia.

Wechsler, I.S. (1933). Partial cortical blindness with preservation of color vision. Report of a case following asphyxia (carbon monoxide poisoning?).Archives of Ophthalmology,9, 957-965.

Zeki, S., Aglioti, S., McKeefry, D., Berlucchi, G. (1999). The neurological basis of conscious color perception in a blind patient.Proceedings ofthe National Academy ofSciences ofthe United States of America, 96, 14124-14129.