Visual Development in the Human Fetus, Infant, and Young Child

The development of the visual system is the most studied of the sensory systems. The advances in technology have made it possible to study the neuroprocesses at the cellular and circuit level. The physical structure of the eye develops early in fetal life, whereas the neurocomponents and connections develop in later fetal and early neonatal life. The development of the visual system involves genetic coding, endogenous brain activity, exogenous visual stimulation after birth at term, and protected sleep cycles, particularly rapid eye movement sleep. Before birth at term, the fetus requires no outside visual stimulation or light. The critical element in development of the visual system before birth at term is protection of rapid eye movement sleep and sleep cycles. Sleep deprivation or disruption in utero and early months of neonatal life causes significant interference with visual development resulting in loss of the topographic relationships between the retina, the lateral geniculate nucleus, and the primary visual cortex in the infant.