Optic neuritis is a common cause of visual loss in young patients. Visual function generally spontaneously improves over weeks, and 95% of patients return to visual acuity of at least 20/40 within 12 months. The initial magnetic resonance imaging (MRI) helps stratify the risk of multiple sclerosis in patients with acute isolated optic neuritis. High-dose steroids hasten the rate, but not the final extent, of visual recovery in optic neuritis, and the decision to use this therapy is individualized. Interferon therapy should be considered in selected high-risk patients.