Tools+of+Science+and+Math+5

=Tools of Science and Math 5 -- Digital Iris Scanner for Security Identification (ID)=

The iris of the eye has been described as the ideal part of the human body for __biometric identification__ for several reasons:

 * ===It is an internal organ that is well protected against damage and wear by a highly transparent and sensitive membrane (the [|cornea]). This distinguishes it from fingerprints, which can be difficult to recognize after years of certain types of manual labor.===
 * ===The iris is mostly flat, and its __geometric configuration__ is only controlled by two complementary muscles (the sphincter pupillae and dilator pupillae) that control the diameter of the pupil. This makes the iris shape far more predictable than, for instance, that of the face.===
 * ===The iris has a fine texture that—like fingerprints—is determined randomly during embryonic [|gestation]. Even genetically identical individuals have completely independent iris textures, whereas DNA (genetic "fingerprinting") is not unique for the about 0.2% of the human population who have a genetically identical [|twin].===
 * ===An iris scan is similar to taking a photograph and can be performed from about 10 cm to a few meters away. There is no need for the person to be identified to touch any equipment that has recently been touched by a stranger, thereby eliminating an objection that has been raised in some cultures against fingerprint scanners, where a finger has to touch a surface, or retinal scanning, where the eye can be brought very close to a lens (like looking into a microscope lens).===
 * ===Some [//[|who?]//] argue that a focused digital photograph with an iris diameter of about 200 pixels contains much more long-term stable information than a [|fingerprint]. [//[|citation needed]//] ===
 * ===The originally commercially deployed iris-recognition algorithm, [|John Daugman]'s IrisCode, has an unprecedented [|false match] rate (better than 10−11).===
 * ===While there are some medical and surgical procedures that can affect the colour and overall shape of the iris, the fine texture remains remarkably stable over many decades. Some iris identifications have succeeded over a period of about 30 years.===

posted by Allen: March 23, 2011