Iris Recognition

Historic techniques for establishing a person’s identity are characterized by many shortcomings. Identification documents may be forged or altered, signatures are difficult to authenticate and verify, tokens or seals may be stolen or counterfeited, and physical descriptions are difficult to quantitatively assess. Establishing identity continues to be important for the same purposes it has been for centuries-for banking transactions, establishing legal presence, entering contracts, gaining entry to secured premises, identifying fugitives, etc-but recently biometrics, described as the science of recognizing an individual based on his physiological or behavioral traits, has gained increasing acceptance as a legitimate method for these tasks. while forms of biometrics have been used to attempt to establish the identities of prisoners and felons for well over a century, the commercial and civilian applications of biometric techniques have only recently begun to be deployed on the large scale.

The human iris, a thin circular diaphragm lying between the cornea and the lens, has an intricate structure with may minute characteristics such as furrows, freckles, crypts, and coronas. For every person, these characteristics are unique as a result of the individual characteristics that arise in the development of anatomical structures during embryonic development. Apart from general textural appearance and color, the finely detailed structure of an iris is not genetically determined but develops by a random process. The iris patterns of the two eyes of an individual or those of identical twins are completely independent and uncorrelated. Additionally, the iris is highly stable over a person’s lifetime and lends itself to noninvasive identification because it is an externally visible internal organ.