Our bodies have taken millions of years to have evolved to this stage. During most of that span, there were no clocks that would tell time as specifically as today’s. Humans would wake up, sleep and stay awake during the day due to circadian rhythm and light. During the day, sun’s bright and blue sunlight would keep us awake and prevent us from falling asleep in the noon. Light kind of used to guide us; absence of light meant “it’s time to sleep” and its presence said otherwise. Consequently for millions of years, humans have been dependent upon light for circadian rhythm.
Then… Edison invented bulbs and suddenly humans found themselves stay awake late at night. Bright, blue sunlight-like signals our brain to inhibit production of sleep hormone, Melatonin. Darker or reddish light signal brain to secrete Melatonin, causing us to feel sleepier. f.lux is a computer application that helps you reduce eye strain and get better sleep earlier. It basically change display temperature of your computer screen according to the time of the day.
How it works:
The theory behind f.lux is that computers produce a blue sunlight-like light. This light inhibits the production of Melatonin, causing to not feel sleepier when it’s time to. This light basically fools the human brain into thinking “it’s still noon”, so it doesn’t release Melatonin. Staring into computer screen at night also causes eye strain and bad sleep.
f.lux simply takes away that “blue” element of light emitting from your computer screen. It makes your screens glow a reddish light. Of course, this is still largely light, however, it lacks the element that’s responsible for messing with Melatonin. f.lux will make your computer display temperature warmer at night than at day. This way, you should be relieved from eye strain and have better sleep – since you’re no longer staring into the sunlight-like light like before.
This is how the screen looks with f.lux in action: