Several technologies related to eyes are proposed:
- Retina vessels is the oldest: reading the retina blood vessels
- Retina photon proposes to use the sensitivity of the retina to photon, which is not the same everywhere
- Iris is the major technique: reading the structure of the iris
- Eye vein is a recent proposal: reading the blood vessels on the eyeball, each side of the iris
- Corneal surface topography reads the cornea surface to create a map
- Eye movement tracking recognize your eye movement when following a target on a screen
- Periocular biometric refers to the facial region in the immediate vicinity of the eye
- (2017) Ocular biometrics in the visible spectrum: A survey / Ajita Rattani, Reza Derakhshan.