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Stiles—Crawford effect and the bleaching of cone pigments
Author(s) -
Coble J. R.,
Rushton W. A. H.
Publication year - 1971
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1971.sp009568
Subject(s) - densitometer , foveal , brightness , optics , pupil , illuminance , densitometry , pigment , flicker , chemistry , physics , retinal , computer science , computer graphics (images) , biochemistry , organic chemistry
1. The efficiency of light entering the eye through various points in the pupil (Stiles—Crawford effect) was studied using two criteria: ( a ) visual brightness judged by flicker fusion and ( b ) the rate of cone pigment bleaching measured by reflexion densitometry. 2. Both measurements were made in the same apparatus with the same geometry of presentation and both gave the same Stiles—Crawford effect. 3. This suggests that the densitometer measures pigment deep in the outer segments of the cones where light is absorbed for vision. 4. Foveal cones seem all to point in the same direction, since the fraction of pigment bleached by light entering the pupil at any one point is the same when measured by light entering anywhere.