In dim light, the iris expands the pupil to allow more light to enter the eye. So, when we come out of a darkroom into the bright sunlight, a large amount of light enters into our eyes and due to glare feeling, we are not able to see the things clearly. Gradually, the iris contracts the pupil to allow less light to enter the eye to see the objects clearly. It take some time for the pupil.For that time interval, person is unable to see the things.
