A 42-year-old white woman suffering from mild euthyroid Graves orbitopathy for 6 years experienced recent-onset upper eyelid swelling, double vision, diminished vision, and reduced visual field of the right eye. Examination of the right eye showed decreased visual acuity, relative afferent pupillary defect, hypotropia with severely restricted elevation, upper visual field defect, impaired color contrast discrimination, and abnormal pattern visual evoked potential, but the Ishihara color plate reading and the optic disc appearance were normal. The left eye was normal, except for marked elevation restriction. On CT scan, the inferior rectus muscles were asymmetrically enlarged. These findings were suggestive of unilateral dysthyroid optic neuropathy, and a 2-week course of pulsed high-dose intravenous corticosteroids was subsequently administered. Since there was no improvement, the clinical examinations and tests were repeated, with the patient positioned in chin lift so that the right hypotropic eye was looking straight ahead. All tests normalized instantly and completely.