Often parents ask if the baby can sleep with the night light on, thinking that it is convenient to help the baby feed and change diapers, and some parents also think that this will make the baby more secure and reduce the child’s fear of the dark. This is actually not the right approach. It is best not to turn on the night light when your baby is sleeping. Foreign studies have shown that sleeping with the lights on is likely to bring a series of unhealthy to the human body, and can even cause cancer, diabetes and other diseases, children sleep in the environment with light for a long time, and may cause premature sexual maturity of the baby. Light affects the secretion of melatonin in the pineal gland of the human brain, and melatonin is directly related to the quality of sleep, which in turn affects the overall immune function of the person.