Conjunctiva
The conjunctiva is a thin, clear membrane that covers the inner surface of the eyelid and the white part of the eyeball (the sclera). It contains many tiny blood vessels.
Inflammation of the conjunctiva is called conjunctivitis. It makes the surface over the white part of the eye look red.
The eye is the organ of sight, a nearly spherical hollow globe filled with fluids (humors). The outer layer or tunic (sclera, or white, and cornea) is fibrous and protective. The middle layer (choroid, ciliary body and the iris) is vascular. The innermost layer (the retina) is nervous or sensory. The fluids in the eye are divided by the lens into the vitreous humor (behind the lens) and the aqueous humor (in front of the lens). The lens itself is flexible and suspended by ligaments which allow it to change shape to focus light on the retina, which is composed of sensory neurons.
References
Dutton JJ. Clinical anatomy of the eyelids. In: Yanoff M, Duker JS, eds. Ophthalmology. 6th ed. Philadelphia, PA: Elsevier; 2023:chap 12.1.
Folberg R. The eye. In: Kumar V, Abbas AK, Aster JC, eds. Robbins & Cotran Pathologic Basis of Disease. 10th ed. Philadelphia, PA: Elsevier; 2021:chap 29.
Version Info
Last reviewed on: 11/8/2023
Reviewed by: Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
