Which term describes the pupil?

• A. The jellylike tissue behind the lens
• B. The light-sensitive cells that respond to color
• C. The hole that lets light into the eye
• D. The tough white outer coat of the eyeball

Answer: (C)

Think about how light gets into the eye. The pupil is the opening in the center of the iris that light passes through to reach the inside of the eye. It acts like a doorway, opening wider in dim light and narrowing in bright light to control how much light reaches the retina. The other descriptions refer to different parts: behind the lens is the jellylike vitreous humor, the light-detecting cells are the rods and cones in the retina, and the tough white outer coat is the sclera. So the term describes the hole that lets light into the eye.