Which of the following eye scan methods is considered to be more intrusive?

A.
Iris scans

B.
Retinal scans

C.
Body scans

D.
Reflective scans

Explanation:
There are two types of eye scan in use today for authentication purposes: retinal scans and iris
scans. Retinal Scan technology maps the capillary pattern of the retina, a thin (1/50th inch) nerve on
the back of the eye. To enroll, a minimum of five scans is required, which takes 45 seconds. The
subject must keep his head and eye motionless within 1/2″ of the device, focusing on a small
rotating point of green light. 320 – 400 points of reference are captured and stored in a 35-byte field,
ensuring the measure is accurate with a negligible false rejection rate.
This compares to 30-70 points of reference for a finger scan. Unfortunately a retinal scan is
considerably more intrusive than an iris scans and many people are hesitant to use the device
[Retina-scan]. In addition a significant number of people may be unable to perform a successful
enrolment, and there exist degenerative diseases of the retina that alter the scan results over time.
Despite these disadvantages, there are several successful implementations of this technology
[Retina-scan].