Also known as Graves' disease, is associated with a hyperactive thyroid gland and may develop at any age and in either sex. The cause of Graves' disease is unknown. When Graves' disease affects the eyes, they may bulge or appear red and swollen, the space between the lids may widen, excess tearing and discomfort may occur and there may be sensitivity to light, blurring or double vision, inflammation, or decreased eye movement. Although Graves' disease may affect comfort, vision, or appearance, many of these problems can be treated successfully. Through discussions with your physician will help determine an appropriate treatment plan.