Bacterial conjunctivitis

Bacterial conjunctivitis is an eye infection in which bacteria inflame the thin membrane over the eyeball and under the eyelids, causing redness. Conjunctivitis is common in children and adults, with bacteria and viruses the leading infective causes, and newborns can acquire it from bacteria in the birth canal. Infection spreads easily by contact with an affected person, and contact lens wear, a recent respiratory infection and dry eyes make it more likely. Typical features are red, gritty, itchy, watering eyes with sticky discharge that crusts the lashes overnight; pain or light sensitivity suggest a more serious problem, and newborn infection needs prompt treatment to protect sight. Clinicians examine the eyes and may swab the conjunctiva for laboratory analysis. Antibiotic eye drops or ointment treat bacterial cases and usually give a good outcome, whereas viral and allergic forms do not respond to antibiotics, and many mild cases clear without treatment.

Seek emergency care for sudden loss of vision, a painful red eye, or flashes and floaters that appear suddenly. See an eye specialist for gradual vision change, halos around lights, or a family history of glaucoma. Call the local emergency number for any symptom that is sudden and severe. This page is a reference for healthcare professionals and does not replace an assessment.