Novel organelles in primate retinal epithelium.

•Two similarly vacuolated organelles, not identified before, differ in their chemical composition.•The first contains melanin and occurs predominantly in young monkeys.•The second organelle does not contain melanin and is more common in old monkeys.•This suggests reorganization or degradation of melanin-containing organelles with age.•Analytic EM can distinguish organelles when mere observation fails to do so easily.