parietal eye; third eye; pineal eye
Anatomical term for a photosensitive organ on the top of the head in some reptiles, amphibians, and fish. Not to be confused with the mystical 'third eye' concept, though the term is sometimes used in that context.
The lizard's parietal eye is an organ that senses light.
Fossils show that ancient reptiles also had a parietal eye.
Commonly used for the mystical or spiritual 'third eye', whereas 顱頂眼 is the scientific anatomical term.
Compound of 顱頂 (ろちょう, 'top of the head') and 眼 (がん, 'eye'). The exact historical derivation is uncertain; the term is used in modern biological contexts.