Conjunctivitis is often called “pink eye.” It happens when the conjunctiva is irritated by an infection or allergies. Your eyes are red and swollen (inflamed), and sometimes they have a sticky discharge. You can have conjunctivitis in one or both eyes. Some types of pink eye are very contagious (easily spread from person to person).

There are three main types of conjunctivitis.

Viral conjunctivitis is the most common type of pink eye. This conjunctivitis is very contagious and often spreads through schools and other crowded places. It usually causes burning, red eyes with a watery discharge.

Bacterial conjunctivitis is also very contagious. An infection from bacteria causes this form of pink eye. With bacterial conjunctivitis, you have sore, red eyes with a lot of sticky pus.

Allergic conjunctivitis is a type of pink eye that comes from an allergic reaction to something. It is not contagious. Allergic pink eye makes your eyes very itchy, red and watery.