Directional model analysis of the spectral reflection from the fovea and para-fovea.

Directional and nondirectional spectral reflection data from 0, 1, 2, 4, and 8 deg eccentricity, and the optic disk, were analyzed from 400 to 950 nm with an existing optical reflection model. The optical model, developed for the fovea, appeared to be also suitable for more eccentric locations. The optical densities of melanin and of the macular pigments zeaxanthin and lutein peaked in the fovea, in correspondence with literature data. The amplitude of the directional component, originating in the cone photoreceptors, had its maximum at 1 deg. The maximum of the directionality (peakedness) occurred at a slightly higher eccentricity.