In six months, color vision and eye movements have developed. In a year 3-D depth perception is completed. More brain space is devoted to vision than all of the other senses combined. From the eye, visual images go to the occipital lobe for processing with cones and rods, but then must be passed on to other areas of our brains to make sense of the messages. One path is to the brainstem which controls eye movements, another path is to the thalamus, which send information to different areas of the cerebral cortex.
Visual experiences are essential for the proper development of the brain circuits underlying vision.
Hubel and Wiesel were the first to experiment with depriving kittens and monkeys of normal visual experiences during early development. Their work won the Nobel Prize. The critical period for wiring human vision is the first two years, with some plasticity through age nine. Visual experiences create the neuronal connections which wires the brain appropriately. At birth a baby has been hearing for about 12 weeks.