The change in the neutral point of dichromats with change in the angle of incidence of monochromatic light on the retina.
The hypothesis was tested that the change in the perceived color of monochromatic light with change in its angle of incidence on the retina can be accounted for completely by prereceptor factors alone. This was evaluated by measuring the change in the match of a monochromatic light to a fixed (and normally incident) white light as the monochromatic beam changed its traverse through the eye from chief ray to "off-axis" retina incidence at the margin of the exit pupil. Two protanopes and four deuteranopes were tested. In each case, the wavelength of the chief ray at the match was consistently, reliably, and (statistically) significantly larger than that of the match with the "off-axis" beam. The result cannot be accounted for by prereceptor factors alone.
Alpern
M
M
Department of Ophthalmology, University of Michigan, W.K. Kellogg Eye Center, Ann Arbor.
Noji
J
J
D003118:Color Perception / Q000502:physiology*; D006801:Humans; D008027:Light; D008433:Mathematics; D055095:Optics and Photonics; D012160:Retina / Q000502:physiology*; D014787:Vision Tests / Q000379:methods; D014796:Visual Perception / Q000502:physiology