Thyroid eye disease (TED), also known as Graves' ophthalmopathy, is an autoimmune disorder affecting the eyes that is commonly associated with Graves' disease and hyperthyroidism. It causes inflammation and swelling of the muscles and fatty tissues behind the eyes. The document discusses the epidemiology, risk factors, pathogenesis, clinical features including proptosis, lid retraction, optic neuropathy, and restrictive myopathy, as well as treatments such as steroids, radiation, orbital decompression surgery, and eyelid surgery. Management involves treatment of both the eye symptoms and any underlying thyroid abnormalities.