Red eye is a term used to describe an eye that appears red due to illness or injury. It usually refers to an increased and excessive amount of blood in the inner surface of the eyelid. Causes of red eye include conjunctivitis, acute glaucoma, injury, dry eye syndrome, a burst blood vessel and drug use. Red eye disease is very contagious. It can be spread through body contact, especially handshaking.
Attribution: Straight Talk Foundation