Iris scanning is a biometric identification procedure in which the user's iris is captured by a high-resolution imaging system and compared to the user's iris image on file. The iris has a complex structure of fibers in it in a pattern unique to the individual, with an even higher complexity than a fingerprint.

In addition to being a noncontact system that can be used in clean rooms and other locations where faces and fingers would be masked, the system can even be used to identify animals. Iris recognition increases the number of choices open to system designers.

Besides being a secure method of identification, an iris recognition system is a more appealing option for the user and therefore is suitable for white-collar secure environments, where a fingerprint recognition system may be viewed as too low-rent.

The advantage of an iris-scanning system over a retina-scanning system is that the former is less invasive, as the stand-off distance is greater, and the time needed for the user's head to remain still (a function of the viewing angle into the eye) is significantly reduced.