"Retina scans are the most accurate form of biometric authentication and are able to differentiate between identical twins." Biometric accuracy levels from high to low are: Retina, Iris, Fingerprint, Hand Print, Hand Geometry, Voice Pattern, Keystroke pattern, Signature dynamics A previous question had it the other way around! Page 6 of this link verifies this: I had to verify myself, because I had seen otherwise on more than one question from various sources during study for this. I ran into a question on here with the answer different than this. ( It said the Iris was more accurate because the retina can show changes such as disease.)<- Incorrect. Retina is less acceptable because it can show disease, but is still more accurate. So which one is the correct answer? The correct answer is retina.

https://www.sans.org/reading-room/whitepapers/authentication/biometric-selection-body-parts-online-139

(Iris has < 0.5% CER, Retina has 1.5% CER. Iris has better accuracy.)<-Incorrect