What changes in size, in order to regulate the amount of light that enters the eye?

Question

Quizplus · Accepted Answer

The pupil changes in size in order to regulate the amount of light that enters the eye. When it is bright, the muscles in the iris contract, making the pupil smaller. Conversely, in dim light, the muscles in the iris relax, making the pupil larger to allow more light to enter. The cornea is the clear, outermost layer of the eye that helps to focus light, the retina is the layer of cells that detect light and the lens helps to focus light onto the retina, but none of these structures change in size to regulate the amount of light entering the eye.

What Changes in Size, in Order to Regulate the Amount