Development of the human visual system: monocular and binocular pattern VEP latency.

Pattern visual evoked potentials (P-VEPs) were recorded in 161 human infants who were between 3 weeks and 2 yr of age. The latency of the first reproducible positive peak in the P-VEP was measured monocularly and binocularly for five sizes of phase alterations checkerboard stimuli (range: 120' to 7.5' check widths). Rapid visual maturation in the first 6 months of life was shown by the development of reproducible P-VEPs to smaller check sizes and by a rapid decrease in the latency of the first reproducible positive peak. Monocular P-VEPs have slightly longer latencies than the binocular P-VEPs. This latency difference is invariant with age, but is significantly greater with larger check stimuli. Normal ranges for this large population are provided as a reference for clinical studies.