Newborns should not be able to turn on the light when sleeping, because turning on the light will cause newborns to have adverse reactions. The first is to cause sleep rhythm disorder, in the newborn sleep to create a good environment, to ensure that the environment is dark and quiet. If you turn on the light to sleep will cause the illusion of newborns, in the daytime can not sleep, and thus is not conducive to sleep, which is an inappropriate way. Secondly, there will be precocious puberty as well as delayed development because growth hormone is secreted rapidly during sleep. If the light is turned on for a long time, it will make the secretion of growth hormone decrease and precocious puberty appear, so it is not suitable to turn on the light when the newborn sleeps.