Sleeping with the lights on for a long time can easily affect the growth and development of children, affect the quality of sleep, and affect the development of eyesight. 1. Impact on growth and development: when children sleep with the lights on for a long time, it may be easy to inhibit the secretion of melatonin, causing melatonin to regulate the release of growth hormone, affecting the growth and development of children. 2. Affect the quality of sleep: If children sleep for a long time when the light is on, can not enter a deep sleep, so that the central nervous sympathetic brain is in a state of excitement, affecting the quality of sleep, mental depression during the day, poor concentration and so on. 3. Impact on vision development: children sleep with the lights on for a long time, the light will stimulate the children’s eyes, resulting in the eyes can not get enough rest, may affect the normal development of vision. Parents try to avoid letting children sleep with the light on, if there are symptoms of discomfort, should be promptly to the regular hospital pediatrics, clear cause of the disease and follow the doctor’s instructions for treatment.