"Just step up to the camera while your eye is scanned. And don't try to play tricks. The iris—the colored part of the eye the camera will be checking—is unique to every person, more so than fingerprints....

The system works like this: when a customer puts in a bank card, a stereo camera locates the face, finds the eye and takes a digital image of the iris at a distance of up to three feet.

The resulting computerized 'iris code' is compared with one the customer will initially provide the bank. The ATM won't work if the two codes don't match."
—Alan Sayre, "Forget the PIN, just look into the camera," The Associated Press