What structure controls the amount of light that enters the eye?
1 Answer
Sep 23, 2016
The Iris and the muscles that control the Iris determine how much light enters the eye.
Explanation:
The pupil is a hole in the Iris that allows light into the eye. The Iris is like the shutter on a camera that can open or close.
When the Iris enlarges it reduces the size of the pupil allowing less light into the eye.
When the Iris is pulled back by the muscles controlling the Iris the pupil enlarges allowing more light into the eye.
A fun experiment is to encourage students to look deep into the eyes of their chosen partner. Then turn off the all the lights at once.
The students should observe the pupil getting larger. Then turn on all the lights at once. The students should observe the pupil shrinking rapidly.
