Abstract
1. Optical reflectance spectra of the fovea were measured in ten subjects with normal colour vision, ten protanopes and seven deuteranopes. Four conditions were used: perpendicular and oblique angle of incident and reflected light on the retina, both in a dark-adapted and a fully bleached state. 2. The spectra were analysed to assess the effects of dichromacy on the cone mosaic. A replacement model, i.e. one where the total number of cones remains unchanged and all cones are filled with a single type of pigment, was found to fit our data best. 3. The analysis of the spectral fundus reflectance also provided estimates for densities of photo-labile and photo-stable retinal pigments and fraction of long wavelength-sensitive (LWS) cones. Visual pigment density was 0.39 for protanopes and 0.42 for deuteranopes, significantly lower than the 0.57 found for colour normals. Macular pigment density was 0.54 for colour normals, 0.46 for protanopes and 0.42 for deuteranopes. 4. For colour normals the LWS cone fraction was 0.56, in agreement with psychophysical literature. The LWS cone fraction for protanopes was -0.04, and for deuteranopes 0.96, consistent with their Rayleigh matches.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Alpern M., Wake T. Cone pigments in human deutan colour vision defects. J Physiol. 1977 Apr;266(3):595–612. doi: 10.1113/jphysiol.1977.sp011784. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bowmaker J. K., Dartnall H. J. Visual pigments of rods and cones in a human retina. J Physiol. 1980 Jan;298:501–511. doi: 10.1113/jphysiol.1980.sp013097. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burns S. A., Elsner A. E. Color matching at high illuminances: photopigment optical density and pupil entry. J Opt Soc Am A. 1993 Feb;10(2):221–230. doi: 10.1364/josaa.10.000221. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cicerone C. M., Nerger J. L. The density of cones in the fovea centralis of the human dichromat. Vision Res. 1989;29(11):1587–1595. doi: 10.1016/0042-6989(89)90140-5. [DOI] [PubMed] [Google Scholar]
- Cicerone C. M., Nerger J. L. The relative numbers of long-wavelength-sensitive to middle-wavelength-sensitive cones in the human fovea centralis. Vision Res. 1989;29(1):115–128. doi: 10.1016/0042-6989(89)90178-8. [DOI] [PubMed] [Google Scholar]
- Dartnall H. J., Bowmaker J. K., Mollon J. D. Human visual pigments: microspectrophotometric results from the eyes of seven persons. Proc R Soc Lond B Biol Sci. 1983 Nov 22;220(1218):115–130. doi: 10.1098/rspb.1983.0091. [DOI] [PubMed] [Google Scholar]
- DeMarco P., Pokorny J., Smith V. C. Full-spectrum cone sensitivity functions for X-chromosome-linked anomalous trichromats. J Opt Soc Am A. 1992 Sep;9(9):1465–1476. doi: 10.1364/josaa.9.001465. [DOI] [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]
- FRANCOIS J., VERRIEST G. Relation entre l'éclairement et l'acité visuelle dans un groupe de sujets normaux et dans différents groupes d'anomalies congénitales de la vision. Ophthalmologica. 1958 Mar;135(3):193–204. doi: 10.1159/000303302. [DOI] [PubMed] [Google Scholar]
- King-Smith P. E. The optical density of erythrolabe determined by retinal densitometry using the self-screening method. J Physiol. 1973 May;230(3):535–549. doi: 10.1113/jphysiol.1973.sp010202. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacLeod D. I., Webster M. A. Direct psychophysical estimates of the cone-pigment absorption spectra. J Opt Soc Am A. 1988 Oct;5(10):1736–1743. doi: 10.1364/josaa.5.001736. [DOI] [PubMed] [Google Scholar]
- Miller S. S. Psychophysical estimates of visual pigment densities in red-green dichromats. J Physiol. 1972 May;223(1):89–107. doi: 10.1113/jphysiol.1972.sp009836. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mollon J. D., Bowmaker J. K. The spatial arrangement of cones in the primate fovea. Nature. 1992 Dec 17;360(6405):677–679. doi: 10.1038/360677a0. [DOI] [PubMed] [Google Scholar]
- Nathans J., Piantanida T. P., Eddy R. L., Shows T. B., Hogness D. S. Molecular genetics of inherited variation in human color vision. Science. 1986 Apr 11;232(4747):203–210. doi: 10.1126/science.3485310. [DOI] [PubMed] [Google Scholar]
- Pokorny J., Smith V. C., Starr S. J. Variability of color mixture data - II. The effect of viewing field size on the unit coordinates. Vision Res. 1976;16(10):1095–1098. doi: 10.1016/0042-6989(76)90248-0. [DOI] [PubMed] [Google Scholar]
- RUSHTON W. A. A CONE PIGMENT IN THE PROTANOPE. J Physiol. 1963 Sep;168:345–359. doi: 10.1113/jphysiol.1963.sp007196. [DOI] [PMC free article] [PubMed] [Google Scholar]
- RUSHTON W. A. THE DENSITY OF CHLOROLABE IN THE FOVEAL CONES OF THE PROTANOPE. J Physiol. 1963 Sep;168:360–373. doi: 10.1113/jphysiol.1963.sp007197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seiple W., Holopigian K., Szlyk J. P., Greenstein V. C. The effects of random element loss on letter identification: implications for visual acuity loss in patients with retinitis pigmentosa. Vision Res. 1995 Jul;35(14):2057–2066. doi: 10.1016/0042-6989(94)00289-x. [DOI] [PubMed] [Google Scholar]
- Smith V. C., Pokorny J. Psychophysical estimates of optical density in human cones. Vision Res. 1973 Jun;13(6):1199–1202. doi: 10.1016/0042-6989(73)90156-9. [DOI] [PubMed] [Google Scholar]
- Snodderly D. M., Auran J. D., Delori F. C. The macular pigment. II. Spatial distribution in primate retinas. Invest Ophthalmol Vis Sci. 1984 Jun;25(6):674–685. [PubMed] [Google Scholar]
- Stockman A., MacLeod D. I., Johnson N. E. Spectral sensitivities of the human cones. J Opt Soc Am A Opt Image Sci Vis. 1993 Dec;10(12):2491–2521. doi: 10.1364/josaa.10.002491. [DOI] [PubMed] [Google Scholar]
- Vimal R. L., Pokorny J., Smith V. C., Shevell S. K. Foveal cone thresholds. Vision Res. 1989;29(1):61–78. doi: 10.1016/0042-6989(89)90174-0. [DOI] [PubMed] [Google Scholar]
- Vos J. J., Walraven P. L. On the derivation of the foveal receptor primaries. Vision Res. 1971 Aug;11(8):799–818. doi: 10.1016/0042-6989(71)90003-4. [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]
- Wesner M. F., Pokorny J., Shevell S. K., Smith V. C. Foveal cone detection statistics in color-normals and dichromats. Vision Res. 1991;31(6):1021–1037. doi: 10.1016/0042-6989(91)90207-l. [DOI] [PubMed] [Google Scholar]
- van Blokland G. J., van Norren D. Intensity and polarization of light scattered at small angles from the human fovea. Vision Res. 1986;26(3):485–494. doi: 10.1016/0042-6989(86)90191-4. [DOI] [PubMed] [Google Scholar]
- van Norren D., van de Kraats J. Imaging retinal densitometry with a confocal Scanning Laser Ophthalmoscope. Vision Res. 1989;29(12):1825–1830. doi: 10.1016/0042-6989(89)90163-6. [DOI] [PubMed] [Google Scholar]
- van Norren D., van de Kraats J. Retinal densitometer with the size of a fundus camera. Vision Res. 1989;29(3):369–374. doi: 10.1016/0042-6989(89)90085-0. [DOI] [PubMed] [Google Scholar]