Conjunctivitis is an
inflammation of the conjunctiva, the transparent mucous membrane lining the inside of the eyelids and
the white of the eyeball. Normally the white, or sclera, is clearly visible through the conjunctiva, but when the conjunctiva is inflamed, its normally invisible blood vessels become engorged, making the eye appear red.
Conjunctivitis may be caused by many types of infectious agents, as well as by toxic, chemical, and allergenic irritants. The
inflammation is generally associated with a scratchy, sometimes itching sensation and an exudate of mucus or pus. A particularly devastating form of conjunctivitis, which may result in blindness, is caused by gonorrhea; therefore, silver nitrate or penicillin eye drops are routinely administered to newborn infants to treat possible gonorrheal infection of the eye.