Turn off your mobile, lap top and tablets at night
Tablets, phones and laptops generate lots of short wavelength blue light, which interferes with production of our sleep hormone, melatonin. This is normally produced in the mid to late evening, but using screens in the two hours before bed reduces melatonin concentrations by 22 per cent.
Screen time before bed can also mean it takes longer to fall asleep and seems to cut down REM sleep. But if you watch TV bedtime relax -while the light from the box is bright, we normally watch from far enough away to mitigate much of the problem.
Screen time first thing in the morning, however, might help shake off grogginess by stimulating cortisol, which peaks 20 to 30 minutes after waking.