The swept contrast visual evoked potential technique is a quasi-psychophysical method that can help bridge the gap between cell biology and visual performance in studies of ocular dominance plasticity. In mice we found that four days of monocular deprivation diminished the amplitude of evoked potentials from the deprived eye relative to the non-deprived eye. This ocular dominance plasticity was nearly as great in adult mice as in juveniles. The monocular deprivation effect was mediated, at least in part, by enhancement of responses evoked from the non-deprived eye, rather than by depression of responses from the deprived eye.