What part of the eye controls the amount of light entering through the pupil?

Question

Quizplus · Accepted Answer

The iris is the colored part of the eye that surrounds the pupil. It contains muscles that control the size of the pupil and the amount of light entering the eye. When there is bright light, the iris constricts the pupil, making it smaller to reduce the amount of light entering the eye. In dim light, the iris dilates the pupil, making it larger to allow more light to enter.

What Part of the Eye Controls the Amount of Light