Abstract

The density of cones (Williams, 1988; Curcio, 1990, 1991) as well as the relative number of the different cone types (Otake and Cicerone, 1992) in the periphery of the human retina have recently been reported. The placement of individual L and M cones within the photoreceptor matrix at 17° temporal eccentricity is reported here. In this region the 3 min center-to-center spacing of the cones and robust optics have allowed the measurement of spectral sensitivities of single cones. After a rod bleach, a test (0.86 min) of varying wavelength was presented upon cone-isolating backgrounds (Cicerone and Nerger, 1989) in a grid of 1.5 min spacing. The locations of distinct peaks and troughs were replicated between sessions and under various adapting conditions. Spectral sensitivity measurements exclude the possibility that rods or S cones contribute to these determinations. We conclude that these are the locations of individual L and M cones within the receptor mosaic of the human peripheral retina.

© 1992 Optical Society of America