What Is Pinkeye?

This irritated eye condition, which you may hear called conjunctivitis, happens when the conjunctiva -- a thin, transparent membrane that covers your eye -- gets inflamed. Most cases clear up in a few days.

It’s a common disease. Children get it a lot. It can be highly contagious (it spreads rapidly in schools and day cares), but it’s rarely serious. It's very unlikely to damage your vision, especially if you find it and treat it quickly.

Understanding Conjunctivitis


There are several types:

Bacterial strains usually infect one eye but can show up in both. Your eye will put out a lot of pus and mucus.

Viral strains may be the most contagious forms. They tend to start in one eye, where they cause lots of tears and a watery discharge. Within a few days, the other eye gets involved. You might feel a swollen lymph node in front of your ear or under your jawbone.

Allergic types produce tearing, itching, and redness in both eyes. You might also have an itchy, runny nose.

Ophthalmia neonatorum is a severe form that affects newborns. It can be caused by a dangerous bacteria. Get it treated right away to prevent permanent eye damage or blindness.

Giant papillary conjunctivitis is linked with the long-term use of contacts or an artificial eye (ocular prosthesis). Doctors think it’s an allergic reaction to a chronic foreign body in your eye.

What Causes It?

An irritant. It could be a bacterial or viral infection, chemical exposure, or a reaction to eye drops. It can also come from an allergic reaction to pollen, smoke, or other things that bother the eyes. Sometimes it appears after a cold or a sore throat.

Viral pinkeye spreads easily from person to person. Strains include:

Conjunctivitis sometimes results from a sexually transmitted disease ( STD ). Gonorrhea can bring on a rare but dangerous form of bacterial conjunctivitis . It can lead to vision loss if you don’t treat it. Chlamydia can cause conjunctivitis in adults. If you have chlamydia, gonorrhea , or other bacteria in your body when you give birth, you can pass pinkeye to your baby through your birth canal.

WebMD Medical Reference Reviewed by Alan Kozarsky, MD on March 26, 2017



Bradford, D (Editor) Basic Ophthalmology. American Academy of Ophthalmology, 2004.

WebMD Medical Reference provided in collaboration with The Cleveland Clinic: "Conjunctivitis."

© 2017 WebMD, LLC. All rights reserved.