Visual evoked response in transient monocular visual loss.

The pattern-reversal visual evoked response (VER) was recorded in 2 patients during transient monocular visual reduction. In both cases the VER was initially abolished. With recovery of vision there was gradual return of amplitude over a 3- to 8-minute period, while latencies remained unchanged from preattack values. These findings are discussed with regard to current understanding of the origins of the VER and relevant aspects of retinal electrophysiology.