The part of the eye that regulates the size of the pupil is the:
A)extrinsic muscle
B)iris
C)ciliary muscle
D)suspensory ligaments

Question

Quizplus · Accepted Answer

The iris, a circular structure surrounding the pupil, is responsible for controlling the size of the pupil by contracting or relaxing its muscles. This allows more or less light to enter the eye. The extrinsic muscles are responsible for moving the eyeball itself, while the ciliary muscle and suspensory ligaments are involved in focusing the lens.

The Part of the Eye That Regulates the Size of the Pupil