Optic disc drusen are acellular, calcified deposits within the optic nerve head. Optic disc drusen are congenital and developmental anomalies of the optic nerve head, representing hyaline-containing bodies that, over time, appear as elevated, lumpy irregularities on the anterior portion of the optic nerve. The phenotype is Optic disc drusen (HP_0012426, a Human Phenotype Ontology entry). Also known as: Optic nerve head drusen.