You see with your eyes. Light enters the through the cornea. It passes through the pupil. The pupil is the black opening in the coloured part of the eye called the iris. The pupil changes size. In dim light the pupil grows larger to let more light into the eye and in bright light the pupil becomes smaller.
Your sight helps you to understand your surroundings. It lets you see an object's colour, size, shape, movement and distance.
Your sense of sight is important as it warns you of danger, eg. looking for cars when crossing the road.
It is very important to protect your eyes.