What is the purpose of the pupil dilating and constricting?
1 Answer
The size of the pupil is regulated by the Iris to control the amount of light entering the eye and striking the retina.
Explanation:
The pupil itself is only a hole or opening in the front of the eye.
The Iris changes its size to control the amount of light that is allowed to enter the eye and affect the retina.
If the amount of light is too great the light energy entering the eye can damage the retina, or produce so much glare that it is hard to make an image on the retina. The Iris will increase in size decreasing the size of the pupil to reduce the amount of the light coming into the eye.
If the amount of light is too little, the light energy entering the eye is not enough to form a clear image on the retina. The Iris will shrink increasing the size of the pupil allowing more light energy into the eye.
The purpose of the pupil is to allow light into the eye. The size of the pupil is regulated by the Iris to ensure that the amount of light energy is correct and appropriate for the conditions.
