The iris was first suggested for use in biometrically-based recognition of humans over a century ago. This notion stems from clinical observations, developmental biology, and statistical evidence that indicate the structure of individual irises is highly distinctive and stable with age. Recent technological advances have brought to the fore iris recognition systems with enhanced detection capability. The current state of the art for this powerful tool allows the capture of a moving subject's iris pattern from afar, through sunglasses, or even from a reflection. Valuable for national security and law enforcement applications, iris recognition provides a means of covert surveillance, and thus carries strong implications for constitutional and public policy concerns. Several government agencies currently employ considerable biometric databases, facilitating efficient and inexpensive tracking. Iris recognition impacts both physical and informational privacy, and should be construed as a search within the meaning of the Fourth Amendment. The regulatory gap should be addressed in a manner that weighs the benefits ofsecurity against the incursions against privacy and liberty.
Ankerman, Chantelle D., "A Closer Look: Iris Recognition, Forensics, and the Future of Privacy Note" (2017). Connecticut Law Review. 372.