Effect of artificial central scotoma on the spatial contrast sensitivity of normal subjects.

Spatial contrast sensitivity was measured in normal subjects with and without a retinally stabilized artificial scotoma (either circular or rectangular), which precluded foveal vision. Our results indicate that the type of contrast sensitivity loss obtained (predominantly high frequency or overall) depended on temporal factors associated with grating presentation. A predominantly high frequency loss was obtained when grating contrast was turned on and off gradually. An additional low frequency difference was obtained when grating contrast was turned on and off abruptly.