The hazards of sleeping with the lights on for children include easy to affect the child’s growth, psychology, eyesight, sleep, etc., as follows. 1. Growth: Sleeping with the lights on tends to inhibit the secretion of melatonin, which regulates the release of growth hormone and directly affects the growth and development of children. 2. Psychological: It is easy to lead to children’s inattention, temperamental, lack of security and other psychological problems. 3. Vision: long-term lights will affect the development of children’s eyesight, many studies have proved that infants and young children sleep with the lights on will increase the chances of developing myopia, vision and two years old before the sleep light source brightness has a close correlation. 4. Sleep: children sleeping with the lights on for a long time will make the brain’s central nervous system sympathetic, the nerves continue to be excited state, thus affecting the child’s sleep. Therefore, try to avoid letting the child sleep with the light on.