The varied and unpredictable ophthalmic manifestations of Graves' disease are ascribed to an autoimmune reaction in which components of a pathogenic“stew”—thyroglobulin (Tg), anti-Tg antibodies, Tg-anti-Tg complexes, and sensitized lymphocytes—bind with and damage extraocular muscle membranes. The rationale of supervoltage orbital irradiation is discussed, as is patient response.