Why do we need sleep?

Why do we need sleep?

Chris Idzikowski (Director of the Edinburgh Sleep Centre) gives expert video advice on: Why do we need sleep?; How much sleep is recomended each night?; Does the amount of sleep differ between men and women? and more...

It is clearly to rest and recover and that's probably as far as it goes. There are various theories around. Most of them either cover recovery... Others cover perhaps preventing us walking around in the dark and bumping into things because we are not adapted to living in that type of environment. So; two classes of theories.