Iris recognition is one of the best automated method of biometric identification that uses mathematical pattern-recognition techniques on video images of one or both of the irises of an individual's eyes, whose complex patterns are unique, stable, and can be seen from some distance.
Advantages of the technology are that it is the highest quality biometrics with one of the lowest FAR rates. Additionally, the iris pattern is not easily transferred onto surfaces (unlike fingerprint) or easy to copy without consent, making it a very secure option. Furthermore the system operation is usually contactless, making it ideal for medical or other hygienic environments.
Disadvantages are that the position of the camera in relation to eye has to be quite close, making user interoperability more challenging. Furthermore, the technology can be more expensive compared with lower grade fingerprint technology, albeit costs of hardware have fallen dramatically in recent years.