Pink eye, or conjunctivitis, is inflammation of the membranes (conjunctiva) covering the white parts of the eyes and the membranes on the inner part of the eyelids. These membranes react to a wide range of bacteria, viruses, allergy-provoking agents, irritants, and toxic agents, as well as to underlying diseases within the body. Viral and bacterial forms of conjunctivitis are common in childhood, but they occur in adults as well. Pinkeye can occur in people of any age. Overall, however, there are many causes of pinkeye. These can be classified as either infectious or noninfectious. Pinkeye does not cause any changes in vision.