Groups of infant monkeys will be reared with a surgically created strabismus wearing contact lenses to produce anisometropia to simulate conditions producing amblyopia in human infants. The development of amblyopia will be verified with visual evoked potentials. Single units will be recorded in the striate cortex at both central and peripheral visual field points and characterized with respect to binocularity, contrast sensitivity to sine wave grtatings, contrast response functions, and contrast gain control. Differences in cortical physiology between the two types of amblyopia will be sought. The results will be interpreted in light of human psychophysical data on the same conditions.