why does it take some time to see objects in a cinema hall when we just enter the hall from bright sunlight ? Explain in breif?

Explanation

In bright sunlight, the pupil of the eye shrinks to allow lesser light to enter into the eye.
When we enter a cinema hall which is dark, pupil takes some time to increase its size so that more light can enter into our eye to make vision possible. In this time interval, we cannot see objects clearly.