Conjunctivitis , commonly known as pink eye , is an inflammation of the conjunctiva—the thin, transparent membrane that lines the inner surface of your eyelids and covers the white part of your eyeball. While it is often associated with the classic reddish-pink hue, conjunctivitis is a complex condition with several distinct causes, ranging from highly contagious infections to seasonal allergies. The Four Primary Types of Conjunctivitis Understanding the cause of the inflamma