Visual Pathways

Each cerebral hemisphere receives information from the eyes about the opposite side of the visual field. Thus, if you stare directly at the corner of a room, everything to the left of the juncture is represented in your right hemisphere, and vice versa. This is so because half the axons in each optic nerve cross over (at the optic chiasm) to the opposite side of the brain. Normally, each hemisphere immediately shares its information with the other one, but in split-brain patients, severing the corpus callosum prevents such communication.