Occasionally sleep with the light on the child generally does not have any serious harm, but often a long time to turn on the light to sleep, may cause certain effects on the child, such as causing dependence on light, affecting the quality of sleep, harm to the child’s eyesight, and so on. 1. cause dependence on light: if the light is turned on for a long time, it may cause the child’s brain central nervous system to form a dependence on light, thus resulting in a special dependence on light, that is, only when the light is turned on to fall asleep, and turn off the light will not be able to sleep. 2. affect the quality of sleep: long-term sleep with the lights on due to the stimulating effect of light, may lead to increased cortical excitability, thus affecting the quality of sleep, resulting in poor sleep quality, in the long run, for the child’s healthy development is unfavorable. 3. Harm the child’s eyesight: long-term sleep with the lights on, because the lights are more blinding, it is likely to affect the development of the child’s eyesight. As you can see, sleeping with the light on frequently may bring some harm, therefore, parents are advised to avoid the bad habit of sleeping with the light on. If the child is found to have abnormal behavior, it is recommended to seek medical treatment as soon as possible.