ocellus medial ocellus UBERON:0003211 FBbt:00004507 aOC anterior ocellus VFB:FBbt_00004507 fly_anatomy.ontology Medial ocellus located on the ocellar triangle of the dorsal postfrons of the adult head, just anterior to, and in between the two medial ocelli. It has around 75 photoreceptors (Dorkenwald et al., 2024). Each half is formed by one of the two (left and right) eye discs (Jean-Guillaume and Kumar, 2022).