A 12-year-old previously healthy male presents with acute onset of vision loss in both eyes approximately two months ago while in school. He denies any other symptoms at the onset of vision loss. He denies any pain with eye movement, nausea, vomiting, or headaches. He is on no medications and has no history of prior eye problems. He has a relative afferent pupillary defect (RAPD) in his right eye and visual acuity is 20/400 right and 20/200 left. Anterior segment and dilated fundus examination is normal. Fundus photographs are shown above. MRI shows asymmetric T2 hyperintensity of the right optic nerve. The brain and spine are normal. Lumbar puncture is unremarkable.