Many people have already written about the beneficial effects of sleep. It’s one of the most natural needs of a person. Undisturbed, sound sleep is the most important pro-health factors for humans.
It has an effect on general health and and the length and quality of life. During sleep, the cells that have been damaged during the day are under repair. In order to let sleep carry out its proper function, you need to take in mind the quality.
Each of us has a different timeframe for regeneration. For some it’s 5 hours and for others its 10 hours for each day. During the first 2 – 3 cycles we have the deepest sleep, then the non-rapid eye movement cycle happens, during which the body is regenerated. The last 2 – 3 hours is rapid-eye movement sleep, extra. You can deduce that the quality of sleep is dependant upon the depth, not the length. These people were part of a test to see how sleep changes the general appearance of a person. See how their faces change after two days without sleep. On the right side is a person fully rested, on the left is the same person with 2 days of sleep deprivation.
This is what a face looks like after missing two days of sleep.