Which of the following are the types of eye scan in use today?

A.
Retinal scans and body scans.

B.
Retinal scans and iris scans.

C.
Retinal scans and reflective scans.

D.
Reflective scans and iris 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].