Conjunctivitis

Pink eye from viruses, bacteria, or allergy

Overview

Conjunctivitis, commonly called pink eye, is inflammation of the conjunctiva, the thin transparent membrane covering the white of the eye and lining the eyelids, and it is one of the most common eye conditions. Viral conjunctivitis, often caused by adenovirus, typically produces a watery red eye, sometimes with cold symptoms, and is highly contagious. Bacterial conjunctivitis tends to produce thicker yellow or green discharge that can stick the lids together, and antibiotic drops may shorten its course. Allergic conjunctivitis causes itching and watering in both eyes and is associated with hay fever and other allergies. Pain, light sensitivity, or reduced vision are not typical of simple conjunctivitis and can point to more serious conditions such as keratitis, uveitis, or acute glaucoma. Conjunctivitis in newborns, ophthalmia neonatorum, can be caused by organisms acquired during birth, and its prevention with eye prophylaxis at birth, introduced by Carl Crede in the 1880s, was one of the early successes of preventive medicine.