Don’t remember the lessons on eye anatomy from your high school biology class? That’s OK—we have provided the following eyeball illustration and terms just to give you a refresher course. 

Iris: Pigmented tissue lying behind the cornea that (1) gives color to the eye, and (2) controls amount of light entering the eye by varying the size of black pupillary opening; separates the anterior chamber from the posterior chamber.

Cornea: Transparent front segment of the eye that covers the iris, pupil, and anterior chamber and provides most of an eye's optical power.

Pupil: Variable-sized, circular opening in center of iris; it appears as a black circle and it regulates the amount of light that enters the eye.

Lens: Natural lens of eye; transparent intraocular tissue that changes shape to bring rays of light to focus on the retina.

Sclera: The white of the eye; a protective fibrous outer layer covers all of the eyeball except for the part covered by the cornea

Ciliary Body: a ring of muscular tissue behind the iris that helps the eye focus by changing the lens’s shape and also produces a fluid called aqueous humor

Choroid: the vascular layer between the sclera and the retina; the blood vessels in the choroid help provide oxygen and nutrients to the eye

Optic Nerve: Largest sensory nerve of the eye that carries light impulses for sight from the rods and cones in the retina to the occipital lobe of the brain.

Macula: Small, specialized central area of the retina responsible for sharp central vision.

Retina: Part of the eye that converts images into electrical impulses sent along the optic nerve for transmission back to the brain. Consists of many named layers that include rods and cones.

Vitreous: Transparent, colorless, gelatinous mass; fills rear two-thirds of the interior of the eyeball, between the lens and the retina.