Professor of psychiatry at the UCLA School of Medicine, Dan Siegel, studied how to use a cell phone just before sleep affects to our brain and body.

What happens to our bodies when we  bedtime  look at cell phone? People are exposing your eyes to the beam of photons from the screen and they are saying our brains’ stay awake, it is not time to sleep, says Dr. Siegel.

That’s why we go to sleep later, and we don’t sleep between 7 and 9 hours each night, nervous system fail to clean all the toxins and neurons fail to relax.

About 5 percent of people in the world is genetically different and they are satisfied with less sleep, but for 95 percent of the people should be 7-9 hours of sleep.

A little sleep affects to our memory, stress levels, solve problems, even is disturbed  the level of the hormone insulin, which regulates the metabolism  and  will be easier to gain weight.

Dr. Siegel recommended that at least an hour before bedtime get away from all screens that could negatively affect on our brain.

source: Wikipedia