Which term is commonly known as pink eye?

The term that is commonly known as pink eye is conjunctivitis. This condition involves inflammation of the conjunctiva, which is the thin membrane that covers the white part of the eyeball and lines the inner surface of the eyelids. The characteristic redness and irritation associated with conjunctivitis is what gives it the nickname "pink eye."

Understanding the causes of conjunctivitis is important, as it can result from infections (viral or bacterial), allergens, or irritants. The symptoms typically include redness, itching, discharge, and tearing.

In contrast, other terms listed refer to different eye conditions. A chalazion is a blockage of a meibomian gland resulting in a cyst on the eyelid. Hordeolum, commonly known as a stye, is an infection of an oil gland in the eyelid. Ectropion is the outward turning of the eyelid, which can lead to discomfort and exposure of the eye. Each of these terms describes a distinct condition, separate from the inflammation associated with conjunctivitis.