SSCP Question #15: Real Exam Question with Answer & Explanation

Question

What physical characteristic does a retinal scan biometric device measure?

Options

• AThe amount of light reaching the retina
• BThe amount of light reflected by the retina
• CThe pattern of light receptors at the back of the eye
• DThe pattern of blood vessels at the back of the eye

Explanation

Retinal scanning works by mapping the unique pattern of blood vessels on the retina at the back of the eye - this vascular pattern is as unique as a fingerprint and remains stable throughout a person's life, making it highly reliable for identification.

Why the distractors are wrong:

• A & B - Retinal scanners emit a low-intensity infrared light beam, but the device isn't measuring light levels (amount reaching or reflected by the retina); it's using light as a tool to illuminate the structure beneath.
• C - Light receptors (rods and cones) are not what's being mapped; while they exist on the retina, their pattern is not the measured biometric. Blood vessels are what create the unique, scannable pattern.

Memory tip: Think "retinal scan = road map." Blood vessels look like roads branching across the back of the eye - the scanner reads your personal road map that no one else has.

No community discussion yet for this question.