Visual Pathway

The path of electrical impulses from the eye to the brain, resulting in the sense of vision; begins with a photochemical reaction, due to light stimulus, in the rods and cones, causing nerve impulses to be generated in the retinal ganglion cells, which then are transmitted through ganglion axon to the region of the optic disc; impulse continues along fibrous processes within the optic nerve, through the optic foramen and to the optic chiasm (or optic chiasma), where half of the fibers decussate (cross over) to the other side, becoming the optic tract, which terminates in the lateral geniculate body located in the thalamus; fibers then give rise to new fibers, which form the optic radiation fibers that extend out and back through the brain to the cortex (surface of the brain) in a region of the brain called the optical lobes; area of the cortex that receives the optic radiations surrounds the calcarine fissure and is called the striate area, striate cortex, visual area, or Brodmann’s Area 17; gross area of vision in the brain is called the occipital cortex.