Conjunctivitis: What Is Pink Eye?

Conjunctivitis, also known as pink eye, isn't pretty. It is an inflammation of the outermost layer of the eye and the inner surface of the eyelids. In addition to having bloodshot eyes, pink eye causes itching, burning, runny, watery, swollen eyes that tend to crust over at night.

There is not just one cause of pink eye. It can start with allergies and turn into an infection, or can be caused by chemicals getting in the eye. Conjunctivitis can be viral or bacterial in nature. Both bacterial and viral pink eye are contagious. Conjunctivitis can also be caused by allergies or a chemical reaction, neither of which are contagious.



Viral conjunctivitis can follow an upper respiratory tract infection or even occur with the common cold or a sore throat. The viral form of the infection is the one most commonly called pink eye. With viral pink eye, the infection usually starts in one eye and often spreads to the other. There can be a clear or pale discharge.

Bacterial conjunctivitis also usually starts in one eye, frequently spreading to the other. The discharge from the infection is greyish or yellowish and may cause the eyelids to stick together while sleeping.

Allergic conjunctivitis (pictured here) can occur with or follow an upper respiratory tract infection, common cold or a sore throat and produces the same symptoms as pink eye.

Conjunctivitis clears up by itself without treatment within two to five days in 65% of cases. Eye drops or a saline solution may help ease symptoms. Antibiotics are sometimes used for bacterial pink eye, and an iodine solution eye wash is helpful with viral pink eye. A gentle eye cream can help soothe the skin of the eyelids but should be kept out of the eyes to avoid further irritation.

The best way to prevent pink eye is to wash hands before touching the eyes. Never share face towels, wash cloths, sunglasses, etc. with another person.