http://www.newscientist.com/articleimages/mg21328503.100/1-sleep-how-much-we-need-and-what-keeps-us-awake.html

There is some consensus in the world of sleep medicine that being exposed to multiple hours of artificial light before bed can reduce melatonin production. Reduced melatonin production means delayed onset for sleep, less REM and taking longer in the morning to wake up. F.lux and Apple’s Night Shift are two examples of software reducing the short wave blue light on iOS and OS/X screened devices, but the results have been mixed. Scientific American sums up our options nicely.

Via Scientific American:

Do you have any suggestions as to what we can do to reduce our blue-light exposure before bed?

For those who just cannot turn off digital devices, here are a few suggestions: You can dim the brightness of your devices or you can make use of programs that filter out short-wavelength light in the evening. I’ve also heard of modern technologies that use different settings, such as reversing the print so the page is dark and the text is light, which, though untested, are probably beneficial if they reduce the amount of emitted light. But the best and least popular answer would be to simply avoid your devices before going to sleep!

http://spie.org/newsroom/5070-candlelight-style-organic-leds-a-safe-lighting-source-after-dusk#B1

Via Harvard Medical School Study – High Sensitivity of the Human Circadian Melatonin Rhythm to Resetting by Short Wavelength Light:

We report here that the circadian resetting response in humans, as measured by the pineal melatonin rhythm, is also wavelength dependent. Exposure to 6.5 h of monochromatic light at 460 nm induces a two-fold greater circadian phase delay than 6.5 h of 555 nm monochromatic light of equal photon density. Similarly, 460 nm monochromatic light causes twice the amount of melatonin suppression compared to 555 nm monochromatic light, and is dependent on the duration of exposure in addition to wavelength.