A 27 year old woman with Graves' disease developed progressive ophthalmopathy and was noted to have abnormal visual evoked responses (VER). She was treated with high dose prednisone with clinical improvement and return of the visual evoked responses to normal. On withdrawal of steroids symptoms recurred and VER again were abnormal. Orbital irradiation was given with improvement in the ophthalmopathy and VER again normalized. To our knowledge this report represents the first demonstration of improvement in VER with treatment in Graves' optic neuropathy.