When one enters a dim-lit room from bright light, one is unable to see the object in the room for sometime. Explain, why.
In bright light, the iris contracts the pupil of an eye to allow less light to enter the eye. When, we enter a dim-lit room, the iris takes time to expand the pupil of the eye to allow more light to enter it. Thus, for a short time one is unable to see in a dim-lit room.