Binocular visual form deprivation in human infants.

Visual acuity was measured with a preferential looking technique in infants and toddlers with binocular form deprivation. Of the 10 children in the study, there were 5 with congenital cataracts and 5 with uncorrected high refractive errors. Infants with cataract surgery before 2 months of age showed normal early development of visual acuity. A 4 to 6 month delay before treatment resulted in reduced acuity but recovery subsequently occurred. Infants with high hyperopia or astigmatism showed no acuity deficits in the first year of life when tested with optical correction. One case of early meridional amblyopia was detected in the third year of life. The deficit was not permanent and, after a period of optical correction, there was recovery of visual acuity to normal levels.