What is Conjunctivitis?

Conjunctivitis, often called "pink eye," is inflammation of the thin, clear membrane covering the white of the eye and the inside of the eyelid. It causes redness, itching, discharge, and a gritty feeling in the eye, and can affect one or both eyes.

It can be caused by a viral or bacterial infection, or by an allergic reaction to things like pollen or pet dander. Viral and bacterial conjunctivitis are contagious and spread easily through touch, while allergic conjunctivitis is not contagious at all.