MegaSack DRAW - This year's winner is user - rgwb
We will be in touch
Once you've tried this for a few days, you'll never go back to a bright screen in the evening again.
Anyone use? I'm a convert at home and work 
"Ever notice how people texting at night have that eerie blue glow?
Or wake up ready to write down the Next Great Idea, and get blinded by your computer screen?
During the day, computer screens look good—they're designed to look like the sun. But, at 9PM, 10PM, or 3AM, you probably shouldn't be looking at the sun.
f.lux
f.lux fixes this: it makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day.
It's even possible that you're staying up too late because of your computer. You could use f.lux because it makes you sleep better, or you could just use it just because it makes your computer look better."
yeah it's the daddy!
like taking off the handbrake on your monitor
1900K with a G&T ftw
Cheers for this cruzcampo, had not heard of this before but just installed it and giving it a go. Its very subtle but i have noticed how bright the monitor is lat at night - but haven't been bothered to mess around with brightness manually. Darkroom mode is a bit much!
I set my evening lux to around 4400k, find it a perfect tone. Sleep a lot better for it too, apparently bright screens can effect the melatonin hormone
http://www.scientificamerican.com/article/bright-screens-could-delay-bedtime/
I've been using this for a few years now. Really helps with preventing my eyes getting tired if I was working late at night.