Do your puples get larger

Your pupils enlarge in dark light so more light comes in. They constrict in bright light to reduce the amount of light. They are affected by drugs. Many abused/illegal drugs causes the pupils to constrict. This is a neat exercise. Rub the short hairs on the back of your neck below your hairline. Your pupils will constrict and enlarge. It is not known why this occurs. There is a theory that when people lie, their pupils dilate.