How Do Retinal Scanners Work?

Introduction

Just like fingerprints, every human eye is different. This difference is formed through the blood vessel patterns on the retina of the eye, allowing a person to easily be identified by taking a scan of the retina. Retina scans are so accurate in discovering identity that the identity error rate is estimated to be only one in every million.

Reflection

Retina scanners work using the reflection of infrared light off the retina. As infrared light is directed into the eye, some of the light is absorbed, while other light is reflected back to the scanner. The blood vessels on the retina absorb more light, reflecting less light than the tissue surrounding the vessels.

Measurement

The retinal scanner measures the amount and intensity of the light that is reflected back off the eye in 320 places. The intensity is then rated anywhere from zero to 4,095 and mapped inside the scanner. The retinal scanner then uses a sophisticated computer code to interpret the data into an identity. Each time the eye is scanned, the code is compared to other codes in the database to verify identity.

Uses

Retinal scanners are already in use in many applications where security access needs to be closely monitored. This is especially true in government and business applications where military, security, and trade secrets need to be closely guarded. Many banks and other businesses where information security or public security is at risk are also considering using retinal scanner technology in the future. Retinal scanners may eventually limit access to ATMs and may even be used to restrict the ability of those whose licenses have been revoked to drive cars.

References

• Discoveries in Medicine
• Retina Scanner Technology