conjunctivitis pink eye Conjunctivitis - a.k.a. Pink Eye This term describes a group of diseases that cause swelling, itching, burning, and redness of the conjunctiva, the protective membrane that lines the eyelids and covers exposed areas of the sclera, or white of the eye. Conjunctivitis can spread from one person to another and affects millions of Americans at any given time. Conjunctivitis can be caused by a bacterial or viral infection, allergy, environmental irritants, a contact lens product, eyedrops, or eye ointments. At its onset, conjunctivitis is usually painless and does not adversely affect vision. The infection will clear in most cases without requiring medical care. But for some forms of conjunctivitis, treatment may be needed. If treatment is delayed, the infection may worsen and cause corneal inflammation and a loss of vision. Proper examination, diagnosis and treatment of Conjunctivitis, or Pink Eye can only be performed by a licensed eye physician.