by Andrea Campbell
We’ve all seen the futuristic movies with the retinal scanners—usually a chemist character uses the eye reader as a way to enter a facility that houses dangerous chemicals. The camera quickly scans the chemist’s eye and with a swoosh he is admitted into the secure room. Cool, huh? Well, the future is already here.
Pipe Dream Realized
In Golden, Colorado, the Jefferson County Sheriff’s Office was looking for a new way to automate tracking of jail inmates. They needed a tool that was practical, accessible and easy to use. Special Duty Officer James Prichett explains, “In 2005, our jail had a capacity for 1,300 inmates and housed an average of 1,153. On a typical day, staff booked from 50 to 80 persons and handled the final release of approximately 50 inmates. Additionally, approximately 200 inmates were released daily from the facility with passes to work, seek employment, and pursue educational opportunities.” Jefferson County is not alone; these tracking activities are common to large corrections facilities.
But how would it work?
As explained in the law enforcement and corrections periodical Tech Beat, basically iris scanning begins by having the subject look into a mirror mounted on a stationary or handheld device. Using simple audio voice commands, the system gives the subject straightforward directions, such as “come closer,” or “step back,” in order to achieve proper positioning of the iris, which usually takes just a few seconds. Behind the mirror, a high-resolution digital camera captures the iris image, and the system tells the operator that successful capture has occurred. The device then makes an encoded template and compares it with all iris templates stored in the database.
"Once the system captures the iris image, matches are made in less than four seconds,” Prichett says. “Given a template match, indicating that the subject has been enrolled in the system, the operator may display on the device screen basic information about the inmate such as height, weight, date of birth, former address, and work-release facts. Once the system and our mainframe are integrated, perhaps within a year, information such as police record, gang affiliation, active warrants, photograph, and fingerprints will also be instantly available on the screen. If the subject is not already enrolled, the device prompts the operator to enter enrollment information.”
No inmate has been wrongly released or mismatched since the jail started relying on iris biometrics. Says Prichett, “Our experience at the jail is that iris scanning is fast, efficient, and accurate.”
How accurate is retinal scanning?
According to a report issued by Newswise and Loyola University Health System, in retinal scanning, a person looks into a scanner and a ray of light is reflected off the retina, at the back of the eye.
"The configuration of retinal blood vessels is unique to each individual and cannot be altered," says Dr. Brian Proctor, an ophthalmologist at Gottlieb Memorial Hospital in Melrose Park, Illinois.
“You can’t change the back of your eye, so it definitely is a proof-positive method of identification,” Proctor says. “Use of retinal scanning as a means of identification has been around for awhile; technology has now caught up with the idea and advanced computerization including database availability can make this a reality.”
Proctor regularly performs a version of retinal screening in the diagnosis and treatment of certain eye conditions and in preparation for complicated eye surgeries.
Several U. S. senators have proposed retinal scanning as an identification method to aid in immigration reform.