Red eye is a common problem that can affect one or both eyes. The redness associated with red eye comes from blood vessels on the surface of your eye that are expanded (dilated) due to some form of irritation or infection.
Pink eye is an inflammation or infection of the thin, clear covering of the white of your eyeball (the conjunctiva) and the inside of your eyelids. When the small blood vessels in the conjunctiva become inflamed they are more visible making the whites of your eye to appear pink. Also called conjunctivitis, it can affect one or both eyes.