If you exhibit bloodshot eyes for longer than three days and/or you are experiencing any eye pain and vision problems, it is imperative that you consult a doctor who will determine the cause and help you find relief for red eyes. A detailed eye examination as well as your medical history may be required. Your doctor may also perform a physical examination to rule out any other medical condition. Bloodshot eyes are a term commonly used to describe red eyes. They are caused when the small blood vessels on the surface of the eye (sclera) become enlarged and congested with blood. This occurs as a result of insufficient oxygen supply to the cornea or the tissues covering the eyes. Usually, bloodshot eyes are not really a cause for major concern but if eye pain or impaired vision occurs, this may be an indication of a serious problem.