Abstract Summated visually evoked responses (VERs) to monocular and binocular light flash stimulation were obtained simultaneously from each cerebral hemisphere. A total of twenty-two newborn infants and ten young adults served as experimental subjects. Amplitude analyses and inter-hemispheric statistical comparisons showed a significantly greater amplitude of the contralateral VER in infants in response to monocular stimulation. This difference did not reach significance in adults although the trend was maintained. Left-right hemispheric comparisons of amplitude did not reach significance for any group. Inter-hemispheric correlation coefficients were computed and were found to be considerably greater for the adult group. The results were discussed in terms of their relationship to fiber counts in the ipsilateral and contralateral tracts, the respective fiber diameters and functional changes related to progressive myelinization of the developing visual system. Several indices for assessing the degrees of functional maturity of the developing human visual system have been considered.