Definition of Episcleritis:

Episcleritis is an inflammation (irritation and swelling) of the episclera, a membrane covering the sclera of the eye.

Causes, incidence, and risk factors:

The sclera is composed of tissue fibers forming the strong white wall of the eye. It is covered by the episclera, a thin layer of tissue containing many blood vessels that feed the sclera. At the front of the eye, the episclera is covered by the conjunctiva.

Episcleritis is inflammation of the episclera, which occurs when there is no infection. Episcleritis is usually mild and rarely progresses to scleritis. The cause is usually unknown, but certain diseases such as rheumatoid arthritis, Sjogren's syndrome, syphilis, herpes zoster, and tuberculosis have been associated with episcleritis. It is a common condition.