The <i>parafoveal</i> short-wavelength-sensitivity mechanism in a protanopic patient with retinitis pigmentosa was found to lack the secondary (long-wavelength) field-sensitivity mode, a property that is characteristic of Stiles's pi 1 mechanism. The results document that normal protanopic observers also lack this mode and reject the hypothesis that the present measurements reflect a pi 3-like—rather than the pi 1-like—mechanism.
© 1982 Optical Society of America
Rockefeller S. L. Young, "Field sensitivity of the short-wavelength-sensitive mechanism in the protanope’s parafoveal retina," J. Opt. Soc. Am. 72, 1026-1028 (1982)