The optic pathway is the neurotransmission system of vision, which is the neurotransmission pathway of visual information from the retinal receptors to the visual center in the occipital region of the brain. There are more than one million ganglion cells in the retina, and each ganglion cell sends out a nerve fiber that converges into a bundle at the optic disc at the back of the eye to form the optic nerve. The optic nerve passes out of the eye and enters the skull through the orbital optic nerve canal. The optic nerves of both eyes gradually converge toward the midline to form the optic cross, and then move backward toward the sides to form the optic bundle. Most of the nerve fibers of the optic tract travel to the lateral geniculate body of the thalamus, from which they reach the occipital cortex of the brain via the optic radiation.