The size of pupils changes when moving from dim to very bright light. Explain how this change occurs?

In dim light, your pupil expands to allow more light to enter your eye. In bright light, it contracts. Your pupil can range in diameter from 1/16 inch (1.5 mm) to more than 1/3 inch (8 mm). Light detected by the retina of your eye is converted to nerve impulses that travel down the optic nerve.

Explanation:

c. establishing proper sleep hygiene