Leber hereditary optic neuropathy (LHON) is caused by mitochondrial mutations that lead to sequential, subacute vision loss with incomplete penetrance and variable expressivity.1 The most common mutations involve complex I subunits of the electron transport chain causing an energy production-demand mismatch that preferentially affects retina ganglion cells. The fundus can show only subtle vascular changes or appear normal, posing a diagnostic challenge in the acute phase of the disease.