Pink eye (often called conjunctivitis) is 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). Conjunctivitis can be caused by a virus, bacteria or by allergies. Bacterial and viral conjunctivitis are easily spread from person to person. Allergic conjunctivitis is not contagious.