Biometric eye scanners
Biometric eye scanners are advanced imaging technologies that utilize the unique characteristics of the iris and retina to identify individuals. Recognized for their high accuracy, these systems play a crucial role in securing areas that require stringent access control, such as correctional facilities and government installations. Iris recognition, which became commercially available in the late 1980s, involves scanning the intricate patterns of the iris, while retinal recognition focuses on the distinctive blood vessel patterns at the back of the eye. Both methods require individuals to position their eyes close to a scanner for a few seconds, where infrared light is used to capture detailed images.
Iris scanning is frequently employed in prisons to verify the identities of inmates and their visitors, ensuring security during releases and access. Meanwhile, retina scanning, which is more complex and demanding in terms of user cooperation, is primarily reserved for high-security environments like military facilities and power plants. In recent years, advancements in biometric iris recognition technology have enhanced its application in forensics, enabling the identification of deceased individuals through extensive iris databases. Overall, biometric eye scanners offer a reliable and efficient means of automated identity assurance, making them integral to various security protocols.
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Subject Terms
Biometric eye scanners
DEFINITION: Imaging technologies that use the iris or retina of the eye to identify individuals.
SIGNIFICANCE: Biometric eye scanning can facilitate the automated control of access to areas where high levels of security must be maintained, such as correctional institutions and military and government installations that house sensitive materials.
The goal of biometric identification systems is to provide automated identity assurance—that is, the capability to recognize individuals accurately—with reliability, speed, and convenience. The complex nature of the human eye provides two of the most accurate biometric measures available. The iris and the retina, located on the front and back of the eye, respectively, are individually distinguishing structures. Retinal recognition became commercially available in the early 1980s, preceding iris recognition systems by about five years.
The iris is the round, pigmented membrane that surrounds the pupil of the eye. The intricate pattern of furrows and ridges in the iris is randomly formed prior to birth and remains stable from early childhood until death. In a typical iris scan, the person being identified aligns one eye close to a wall-mounted scanner for a few seconds. The scanner uses a near-infrared light to scan an image of the eye, and computer software then isolates the iris in the image and performs size and contrast corrections. Computer software then compares the final digital image with other iris images stored in a database; when a match is made, the person is identified.
Prisons throughout the United States use iris-scanning technology to verify the identities of convicts before release. Correctional facilities also enroll visitors in their iris image databases and scan the irises of people leaving the facilities to be certain they are visitors, not inmates. Some organizations use small, semiportable iris scanners to control access to sensitive computer files and information.
In the 2020s, experts believed that advances in biometric iris recognition have made the technology more valuable to forensics. These advances included the creation of large iris databases and high-resolution video and photography. Experts have successfully used iris recognition to identify deceased individuals.
Retina biometric identification is based on the individually distinguishing characteristics of blood vessel patterns on the back of the eye. These patterns are thought to be created by a random biological process and remain unchanged throughout life in a healthy individual. During retina scanning, the person being identified aligns one eye with a wall-mounted scanner for several seconds. The scanner illuminates the retina with a low-intensity infrared light and creates an image of the patterns formed by the major blood vessels. The image is then digitally encoded, stored, and compared using computer software.
Because the retina is located on the back of the eye, this type of scan requires a high degree of cooperation from the user to ensure proper illumination and alignment. Given that retina scanning is more complex than the iris-scanning process, retina-scanning technology is best deployed in high-security, controlled-access environments where user convenience is not a priority. Employees in military weapons facilities, power plants, and sensitive laboratory environments are commonly required to undergo retina scanning to gain access.
Bibliography
Coats, William Sloan, et al. The Practitioner’s Guide to Biometrics. Chicago: American Bar Association Publishing, 2007.
Matey, James R., George W. Quinn, and Patrick Grother. "Forensic Iris: A Review, 2022." National Institute of Standards and Technology, US Department of Commerce, July 2022, nvlpubs.nist.gov/nistpubs/TechnicalNotes/NIST.TN.2226.pdf. Accessed 14 Aug. 2024.
Nanavati, Samir, Michael Thieme, and Raj Nanavati. Biometrics: Identity Verification in a Networked World. New York: John Wiley & Sons, 2002.
Woodward, John D., Jr., Nicholas M. Orlans, and Peter T. Higgins. Biometrics. New York: McGraw-Hill, 2003.