Contrast sensitivity of the human peripheral retina

Abstract

Threshold contrasts were measured psychophysically for a sinusoidal grating target centered 12[deg] in the peripheral retina. The relationship between contrast sensitivity, the reciprocal of the threshold contrast, and the spatial frequency of the gratings can be adequately described by the difference of two Gaussian functions. The parameters of the fitted Gaussians are used to describe the effects of varying the mean luminance of the target on the shape of the contrast sensitivity function. With increasing luminance the characteristic radii--parameters which are related to the width of the spread function of the visual system--decrease, while the overall contrast sensitivity of the eye increases.