Which of the following eye structures is responsible for controlling the amount of light that enters the eyeball?

Question

Quizplus · Accepted Answer

The pupil is the opening in the center of the iris that controls the amount of light entering the eye. When there is a lot of light, the pupil constricts (becomes smaller) to reduce the amount of light entering the eye. When there is little light, the pupil dilates (becomes larger) to allow more light to enter. The other structures listed (cornea, retina, and lens) do not control the amount of light entering the eye. The cornea is a clear outer layer that helps to focus light onto the retina, the retina is the light-sensitive layer that contains photoreceptor cells, and the lens changes shape to help focus light onto the retina.

Which of the Following Eye Structures Is Responsible for Controlling