Variation in density of macular pigmentation and in short-wave cone sensitivity with eccentricity.

Using both absolute threshold and flicker techniques, we measured the relative spectral sensitivity at different eccentricities during the cone-plateau period of the long-term dark-adaptation curve. With both techniques the relative spectral sensitivity tended to increase with eccentricity in the short-wave region of the spectrum. The results suggest that the relatively high short-wave sensitivity of the extrafovea obtained with the threshold technique, is due both to variation in density of macular pigmentation nd in short-wave cone sensitivity, while the relatively high short-wave sensitivity obtained with the flicker technique is due to variation in density of macular pigmentation alone. The results were used as a basis for analyzing the variation in density of macular pigmentation and in short-wave cone sensitivity with eccentricity.