TL;DR:

Control + ⌘ + Shift + G Home button triple-click.

Why?

Exposing ourselves to bright screens at night while checking our Facebook feed or reddit posts might not be as harmless as it seems. Tons of research, like this and this suggest that viewing things on bright screens right before bed makes our brains think that we’re in daylight longer than we actually are and, consequently, prevent us from falling asleep sooner than we should be. This combined with our early-start culture has been shown to lead to fatigue, decreased concentration and, in some folks, depression.

Additionally, other research has shown that prolonged exposure to artificial light (like those in most offices or our phones) can, over time, damage our eyes’ ability to adjust to incoming light and weaken their sensitivity to it.

I didn’t notice any of this until a Slashdot post introduced me to Flux several years ago. Before using this application, I was usually tired and sore (I rode my bike much more often back then) most of the time, but didn’t think much of it. I went out often back then, and most of the people I came across were just as or more tired than I was, so I thought I was fine.