Thyroid eye disease, also known as Graves' Disease, Graves' Orbitopathy, or Graves' Ophthalmopathy, is a medical problem that causes enlargement of the muscles that move the eye and opens the eyelids too wide. As these muscles slowly enlarge, the eye is pushed forward and its movement is restricted. This causes the patient to have bulging eyes that move poorly and to have a wide stare. The swelling of the muscles can become so severe that the blood flow to the optic nerve is strangled resulting in a slow loss of vision. The appearance and function of the eyes can usually be improved with eyelid and orbital surgery.