A retinal scanner is a human security device which scans the retina of an eye for identity verification and authentication. Individuals attempting to acquire confidential information or gain access to a secured locale must often undergo a retinal scan and a fingerprint or voiceprint scan.[1] They are utilized aboard UNSC starships, space stations, and in various other military complexes.[2][3] They are also commercially available and can be equipped on the doors of residential homes.[4]