Conjunctivitis, kuhn juhngk tuh VY tihs, is an inflammation of the membrane that covers the white part of the eyeball and the inner lining of the eyelid. This membrane is called the conjunctiva. Conjunctivitis may be caused by infections of bacteria, viruses, or other microorganisms. It also may result from allergies or chemical burns. Most types of conjunctivitis caused by infection are contagious.