A retina scan is a biometric identification method that uses the unique patterns of blood vessels in the back of the eye, known as the retina, to verify a person's identity. This technology captures high-resolution images of the retina, which are then analyzed for distinct features. It is often used in security systems and access control due to its high accuracy and difficulty to replicate. The process is non-invasive and typically takes only a few seconds. Retina scans are considered more secure than traditional passwords or PINs, as the retina's patterns are unique to each individual, similar to a fingerprint.