Abstract
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.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BRINDLEY G. S. The effects on colour vision of adaptation to very bright lights. J Physiol. 1953 Nov 28;122(2):332–350. doi: 10.1113/jphysiol.1953.sp005003. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ENOCH J. M., STILES W. S. The colour change of monochromatic light with retinal angle of incidence. Optom Wkly. 1961 Oct;8(52):329–358. doi: 10.1080/713826396. [DOI] [PubMed] [Google Scholar]
- Hood C., Rushton W. A. The Florida retinal densitometer. J Physiol. 1971 Aug;217(1):213–229. doi: 10.1113/jphysiol.1971.sp009567. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Makous W. L. A transient Stiles-Crawford effect. Vision Res. 1968 Oct;8(10):1271–1284. doi: 10.1016/0042-6989(68)90049-7. [DOI] [PubMed] [Google Scholar]
- RIPPS H., WEALE R. A. PHOTO-LABILE CHANGES AND THE DIRECTIONAL SENSITIVITY OF THE HUMAN FOVEA. J Physiol. 1964 Sep;173:57–64. doi: 10.1113/jphysiol.1964.sp007442. [DOI] [PMC free article] [PubMed] [Google Scholar]
- RUSHTON W. A. Kinetics of cone pigments measured objectively on the living human fovea. Ann N Y Acad Sci. 1959 Nov 12;74(2):291–304. doi: 10.1111/j.1749-6632.1958.tb39552.x. [DOI] [PubMed] [Google Scholar]
- Rushton W. A., Henry G. H. Bleaching and regeneration of cone pigments in man. Vision Res. 1968 Jun;8(6):617–631. doi: 10.1016/0042-6989(68)90040-0. [DOI] [PubMed] [Google Scholar]
- Safir A., Hyams L. Distribution of cone orientations as an explanation of the Stiles-Crawford effect. J Opt Soc Am. 1969 Jun;59(6):757–765. doi: 10.1364/josa.59.000757. [DOI] [PubMed] [Google Scholar]
- WALRAVEN P. L., BOUMAN M. A. Relation between directional sensitivity and spectral response curves in human cone vision. J Opt Soc Am. 1960 Aug;50:780–784. doi: 10.1364/josa.50.000780. [DOI] [PubMed] [Google Scholar]
- Walraven P. L. Recovery from the increase of the Stiles-Crawford effect after bleaching. Nature. 1966 Apr 16;210(5033):311–312. doi: 10.1038/210311a0. [DOI] [PubMed] [Google Scholar]