When an eye doctor dilates her patient's pupil, this part of the eye, also distinguished by its color, expands to let more light in.

Question

Quizplus · Accepted Answer

The iris is the part of the eye that is distinguished by its color and controls the size of the pupil, thus regulating the amount of light that enters the eye. When an eye doctor dilates a patient's pupil, they are causing the iris to expand or contract to change the size of the pupil.

When an Eye Doctor Dilates Her Patient's Pupil, This Part