Citation

Pokorny J, Smith VC. Color Res. Appl. 1982; 7(2): 159-164.

Copyright

(Copyright © 1982, John Wiley and Sons)

DOI

10.1002/col.5080070222

PMID

unavailable

Abstract

The majority of research on X-chromosomal defects has been with a 2° field of view. The studies concur in a view of dichromacy as a loss or reduction system, and anomalous trichromacy as an alteration system. According to this view, protanopes have no functional LWS (long-wave-length-sensitive) photopigment; deuteranopes have no functional MWS (middle-wavelength-sensitive) photopigment. With larger fields of view, dichromats show trichromacy which is mediated by rods at low photopic luminances, and by anomalous cones for retinal illuminances above 1000 trolands. These studies suggest that the same (or similar) anomalous (L'WS) photopigment is formed at the protan locus and the same (or similar) anomalous (M'WS) photopigment is formed at the deutan locus for both the anomalous trichromatic and dichromatic forms of the defects. Family studies reveal that intrafamilial variability in chromatic discrimination is less than interfamilial variation. A possible interpretation of such studies is that multiple, rather than three or four, alleles may be involved in X-chromosomal color-vision defects, with the alleles determining the proportion of functional anomalous cones.

Language: en