Sleep disruption from electronics

Ordinarily, the pineal gland begins to release melatonin a couple of hours before your regular bedtime. The hormone reduces alertness and makes sleep more inviting. However, light — particularly of the blue variety — can keep the pineal gland from releasing melatonin, thus warding off sleepiness.

To counteract the effects of  blue light from screen, researchers recommend a free app, F.lux, that automatically warms up the colors on your various screens — more reds and yellows — at sunset and returns them to normal at sunrise.

Wapo: Blue light from electronics disturbs sleep, especially for teenagers