Optic neuritis (ON) is the demyelinating inflammation of the optic nerve head usually associated with multiple sclerosis. It is usually associated with sudden onset loss of vision with dyschromatopsia and retro-orbital pain. Atypical features for a demyelinating ON include the absence of pain, severe visual loss, progression of visual loss, pain for more than 2 weeks, and lack of recovery after 3 weeks. Atypical features in fundus examination include marked swelling of the nerve with retinal exudates, peripapillary hemorrhages and bilateral presentation, which may occur either simultaneously or sequentially. Atypical ON requires careful consideration and differentiation from demyelinating ON and ischemic optic neuropathy since the treatment...