Sensitivity to spatiotemporal colour contrast in the peripheral visual field.

Contrast detection thresholds for spatiotemporal colour modulation were determined at several retinal locations. Colour discrimination is studied for red-green modulation of a yellow field and for yellow-blue modulation of a white field. For constant target size colour vision deteriorates if the stimulus is moved away from the fovea, but if the shift is combined with a suitable enlargement of the target size colour discrimination at the periphery is comparable to that at the fovea. We did not find any retinal location along the horizontal meridian which was red-green or yellow-blue colour blind. Chromatic bars were detected in the nasal peripheral retina at eccentricities of up to at least 50 degrees, temporal colour contrast was perceptible at nasal eccentricities of up to at least 90 degrees.