achromatopsia (MONDO_0018852, a Monarch Disease Ontology entry) (ACHM) is a rare autosomal recessive retinal disorder characterized by color blindness, nystagmus, photophobia, and severely reduced visual acuity due to the absence or impairment of cone function. Also known as: ACHM, Pingelapese blindness, Rod monochromacy, Rod monochromatism, complete or incomplete color blindness, complete or incomplete colour blindness, monochromatism, total color blindness.