Question

why does your pupil contract and relax

Answer 1

Explanation:

In order to regulate the light levels entering the eye, the size of the pupil is adjusted by the iris. ... In bright light, the circular muscles contract whilst the radial muscles relax. This causes the pupil to constrict and less light enters the eye. In dim conditions the opposite occurs.

Answer 2

Explanation:

In bright light, the circular muscles contract whilst the radial muscles relax. This causes the pupil to constrict and less light enters the eye.The circular muscles relax and the radial muscles contract, causing the pupil to dilate and allowing more light to pass into the eye.