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It’s fall! Days are getting shorter (looking forward to the Christmas season), and we’re switching to artificial light earlier and earlier. Of course, a big source of artificial light for many of us is our computer monitors. Whether your computer uses an old CRT-tube monitor, or a new flat panel LCD display, the light that comes out of it is mostly on the blue spectrum. Remember, blue light is close to the color of natural daylight (somewhere around 6500K). But one major signal for our brains to get ready to sleep is red or orange light–between 2000K and 3500K.

Back before the advent of light bulbs and especially before florescent lighting, evenings were lit by softer, yellower light. Incandescent lights come in at 2700K (orange). Campfires, lanterns, and candles are even redder, and also put out a lot less light than an electric or gas lamp.  Without artificial light, evening light swiftly becomes red/orange at sunset, and then turns very dark or a dim, deep blue. When the power goes out from a storm next, and you’re reading by candle light, pay attention to how early you feel tired and fall asleep after dark!

God created people to run on an internal, 24-hour clock, and an important part of that clock is melatonin, sometimes thought of as the sleep hormone. Light entering your eye can suppress the production of melatonin — and that’s a problem if you’re on your computer or in a brightly lit room after sunset. Even if you’re tired from a long day, if the right chemical conditions don’t exist for sleep, you’ll have a hard time nodding off.

This is where a cool program called f.lux can help. F.lux is an app for your computer that controls the backlight in your monitor. Just enter your zip code, and f.lux will automatically adjust the color of your computer screen to go easy on your eyes as the sun rises and sets. (Click settings to add your location–I also like to switch to the slower, 60m transition.)

As soon as I installed f.lux, there was a definite improvement in my ability to sleep right after getting off the computer at night. You can read more research about light and sleep at the f.lux research page. For android phones and tablets, try the Night Filter app from Google Play. Unfortunately, there’s not a good option for apple iOS devices right now, but you can get a plastic applique to put on just at night. Most laptops or monitors will also have a screen brightness adjustment, which I obviously recommend you use as well.

Get f.lux now at and see the difference.