My son is three years old. Why does he always have to turn on the light to fall asleep?

Children turn on the light at night to sleep well, because these children are afraid of being alone in the dark, and he is not used to sleeping alone. To put it bluntly, the child is afraid of sleeping in the dark. He needs to turn on the light to sleep, otherwise he can't sleep.

For turning on the light to sleep, I think it is the psychological barrier of children. They thought they could sleep peacefully under the light; In fact, when I was a child, I always slept with the lights on. If I don't turn on the light to sleep, I will make trouble with my parents. Because I am afraid of the dark, I have to turn on the light when I sleep, and I can't even turn on the light. I want to use headlights, but I don't have to turn on the lights when I sleep with people, because I won't be afraid when I'm around. Later, my parents thought of a way to turn off the lights after I fell asleep, because I usually don't get up after I fell asleep, and then my parents used this method. Until I went to high school, I had to turn off the lights and sleep at eight o'clock, so I was used to turning off the lights and sleeping. Until now, I can sleep alone without turning on the light, but I can't sleep with the light on.

Although turning on the light is to make children sleep well, it is very bad for children to sleep with the light on; The first point is that children's sleep quality will decline, because lighting will bring some invisible pressure to children, and children will not feel pressure; Second, for children's eye vision development, although the eyes are closed, there is no good rest in the light, which will affect their vision; The last point is that children's immunity will decline, because experts say that "a lot of melatonin will be secreted during sleep, which will slow down the heartbeat and rest the heart, thus enhancing immunity."