Graves’ disease is a disorder that causes your thyroid gland to make too much of certain hormones -- a condition called hyperthyroidism. In addition to weight loss, a fast heartbeat, high blood pressure, and irritability, among other symptoms, it also can cause your immune system to mistakenly attack healthy cells. In some people, the muscles and tissue around the eyes are targeted.
About half of people with Graves' disease notice some eye issues, and some have severe vision problems. Experts think this happens because the tissues in your eyes have proteins like ones in your thyroid gland. The problem is known as Graves' eye disease or Graves' ophthalmopathy.
Doctors don't think it can be prevented, but you're more likely to get it -- and have a worse case of it -- if you smoke.