Question

what is the purpose of photoreceptors? (1 point)
○ they contract and relax to control the pupil.
○ they change light to electrical signals.
○ they receive light and turn it into an image.
○ they focus the light coming into the eye.

Explanation:

• Analyze each option:
• Option 1: Muscles (like iris muscles) control the pupil, not photoreceptors.
• Option 2: Photoreceptors (rods and cones in the retina) convert light energy into electrical signals (action potentials) that the brain can interpret. This is their main function.
• Option 3: The brain processes the signals from photoreceptors to form an image, not the photoreceptors directly turning light into an image.
• Option 4: The lens and cornea focus light, not photoreceptors.

Answer:

B. They change light to electrical signals.