Spatial and temporal contrast sensitivity in hemianopia. A comparative study of the sighted and blind hemifields.

Spatial and temporal contrast sensitivity was measured, under identical test conditions using spatially and temporally localized stimuli, in 4 normally sighted human subjects and in 3 healthy hemianopic subjects whose stable visual field loss exhibited foveal sparing. Testing was undertaken at central fixation and at a variety of eccentric loci along the horizontal meridian of the sighted and perimetrically blind field. In comparison with the normal (control) sensitivities obtained in this study, spatial and temporal sensitivities in the sighted hemifield in subjects with striate cortical lesions were both reduced; in addition, we were unable to demonstrate greater-than-chance performance at any extrafoveal locations in the blind hemifield.