Like fingerprints, it is virtually impossible for two human irises to be alike. This means that yours are unique, and even your left and right irises are not the same. For the past decades, the biometric identification industry has been gradually investing in the development of iris recognition systems, which employ pattern-recognition algorithms, camera technology, and near-infrared illumination to identify a person by their unique iris patterns.
The near-infrared illumination enables the camera to record complex iris structures that cannot be seen otherwise. This information is then encoded and stored in a database, allowing for quick pattern comparison and system access. Iris recognition systems continue to be further refined and are being massively deployed in airports and other tight-security environments. Civil rights activists and organizations have voiced concerns over the fact that the technology may facilitate the unauthorized tracking of individuals by authorities (as can our banking transactions and other digital footprints).
Iris scanners are being built into a growing number of smartphones, making access to the device and specific folders by unwanted parties much more complicated, but not impossible. In 2017, the German hacker association Chaos Computer Club demonstrated, in a video, how the Samsung Galaxy S8's iris recognition system could be fooled. Still, Samsung reported that such unauthorized access requires "a rare combination of circumstances," and the security feature was maintained in the following S-series model. Yet, the manufacturer did not include an iris scanner in the subsequent release, the Samsung Galaxy S10.
One of the advantages of iris recognition over fingerprint recognition is that iris patterns remain stable over a person's life (although cataract surgery has been said to have a possible iris-altering effect). Other pros are the ability to perform a scan from afar, with no need for physical contact; higher resistance to false matches; and the possibility of performing a scan without the removal of contact lenses, eyeglasses, and non-mirrored sunglasses, depending on the technology used. Iris scanners are, however, more expensive than fingerprint-based biometrics.
Iris recognition is not to be confused with retinal scanning, another biometric technology that relies on retinal blood vessel patterns.