Optic neuritis (ON) is the inflammation of the optic nerve. 'Typical' ON is commonly associated with multiple sclerosis (MS) and its classic triad includes sudden loss of vision, pain with eye movement and dyschromatopsia. It usually has good visual outcome irrespective of treatment. Presentation other than this is termed as 'atypical' ON and causes include autoimmune diseases, infections and optic neuropathy related to systemic disorders, etc. These cases of ON need specific treatment depending on the cause. Therefore, it is vital to differentiate 'typical' from 'atypical' ON. Here, we present a case of ON associated with MS, which presented with atypical symptoms i.e. painless loss of vision. Moreover, this patient had a poor final visual outcome, in contrast to the generally good visual prognosis of ON associated with MS.