The mitochondrial m.3243A>G variant is known to cause retinal dystrophy and vision loss. We used single cell RNA sequencing to understand how the presence of this mutation affects cellular phenotype in a cell type-specific manner. Overall design: Human retinas were dissected into neural retina and RPE/choroid from two regions (macular and peripheral). Samples were then dissociated to single cells using papain or collagenase respectively. Samples from a MELAS patient and age/sex-matched healthy control donor were prepared.