Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1973 May;230(3):535–549. doi: 10.1113/jphysiol.1973.sp010202

The optical density of erythrolabe determined by retinal densitometry using the self-screening method

P E King-Smith
PMCID: PMC1350613  PMID: 4541511

Abstract

1. Retinal densitometry has been used to determine the optical density of erythrolabe in foveal cones.

2. A self-screening method was used, as in Rushton's (1963b) measurements on chlorolabe.

3. Psychophysical experiments have demonstrated that self-screening in cones depends on the direction of the light in the same manner as the Stiles—Crawford efficiency. Stiles—Crawford measurements were therefore made on each subject and a method was devised to allow for the corresponding reduction in self-screening in densitometry.

4. Complications arising from coloured bleaching products, the presence of a second visual pigment and the fluorescence of visual pigments are considered.

5. The mean value for optical density at 560 nm was found to be 0·40 ± 0·07 S.E. of mean for the five subjects (two deuteranopes, two deuteranomalous subjects and one normal subject).

6. This result is in good agreement with Rushton's (1963b) value of 0·35 for chlorolabe using retinal densitometry.

7. The densitometry results are also in reasonable accord with recent psychophysical and microspectrophotometry measurements. This provides evidence that densitometry measures all the cone pigment in an unbiased manner and not just a superficial sample.

Full text

PDF
535

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Coble J. R., Rushton W. A. Stiles-Crawford effect and the bleaching of cone pigments. J Physiol. 1971 Aug;217(1):231–242. doi: 10.1113/jphysiol.1971.sp009568. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. DARTNALL H. J. A. The interpretation of spectral sensitivity curves. Br Med Bull. 1953;9(1):24–30. doi: 10.1093/oxfordjournals.bmb.a074302. [DOI] [PubMed] [Google Scholar]
  3. Dobelle W. H., Marks W. B., MacNichol E. F., Jr Visual pigment density in single primate foveal cones. Science. 1969 Dec 19;166(3912):1508–1510. doi: 10.1126/science.166.3912.1508. [DOI] [PubMed] [Google Scholar]
  4. 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]
  5. Guzzo A. V., Pool G. L. Visual pigment fluorescence. Science. 1968 Jan 19;159(3812):312–314. doi: 10.1126/science.159.3812.312. [DOI] [PubMed] [Google Scholar]
  6. 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]
  7. MARKS W. B. VISUAL PIGMENTS OF SINGLE GOLDFISH CONES. J Physiol. 1965 May;178:14–32. doi: 10.1113/jphysiol.1965.sp007611. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. 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]
  9. RUSHTON W. A. CONE PIGMENT KINETICS IN THE DEUTERANOPE. J Physiol. 1965 Jan;176:38–45. doi: 10.1113/jphysiol.1965.sp007533. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. RUSHTON W. A. STRAY LIGHT AND THE MEASUREMENT OF MIXED PIGMENTS IN THE RETINA. J Physiol. 1965 Jan;176:46–55. doi: 10.1113/jphysiol.1965.sp007534. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Rushton W. A., Baker H. D. Red--grees sensitivity in normal vision. Vision Res. 1964 May;4(1):75–85. doi: 10.1016/0042-6989(64)90034-3. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES