Contrast evoked potentials in strabismic and anisometropic amblyopia.

Steady-state visual evoked potentials were elicited by the appearance/disappearance of sinusoidal gratings of varying spatial frequency for both eyes of amblyopic subjects. The amblyopic eyes showed reduced responses and a phase shift relative to the nonamblyopic eyes across a wide range of spatial frequencies. Both the nonamblyopic and amblyopic eyes showed a linear relationship between the evoked potential amplitude and the logarithm of the stimulus contrast; however, the slope of the line was flatter for the amblyopic eyes.