Muscles, Nerves, and Blood Vessels

Several muscles working together move the eye. Each muscle is stimulated by a specific cranial nerve (see Section 6, Chapter 96). The optic nerve (a cranial nerve), which carries impulses from the retina to the brain, the lacrimal nerve, which stimulates the tear glands to produce tears, and other nerves, which transmit sensation to the brain from the various parts of the eye, travel through the orbit.

An ophthalmic artery and a retinal artery provide blood to each eye, and an ophthalmic vein and a retinal vein drain blood from the eye. These blood vessels enter and leave through the back of the eye.