A Guide On: Using Blue Light to your Benefit

Altering your blue light exposure is a relatively easy way to hack your sleep and energy, especially since it doesn't require ingesting anything. If you're skittish about doing weird things to yourself, this one is pretty safe.

Blue light has been shown to be highly influential to the circadian rhythm, the biological cycle that makes us sleepy and wakeful. Blue light helps stimulate certain biological processes that make us energized -- this is great during the day, but horrible when you're hoping to get a night of good rest. Studies have shown that exposure to blue light can delay sleep onset (the period of falling asleep) by up to an hour.

In short: 

Blue light at night delays sleep. Avoid it.

  • Avoid screen exposure at night
  • Change the hue on your computer using f.lux
  • Stop using electronics in bed
  • Change the blue lights in your home

Blue light in the day gives you feelings of energy. Use it.

  • Expose yourself to sunlight in the morning
  • Get a sunlight-simulating lamp
  • Get a blue light

Certain sources of light emit more blue light than others. The sun is a great source of blue light. LED and LCD screens (including that sweet Retina display) emit blue light as well. Below is a chart that shows the various light "temperatures" of different light sources.

Avoid Screen Exposure at Night

The LED and LCD screens in TVs, computers, and phones emit loads of blue light. The ideal solution: stop looking at screens at least an hour before bedtime. If you can't entirely avoid it, at least try to minimize your exposure.  For some people, avoiding screen exposure might take a lot of planning.

Ideally, you shouldn't be working within an hour before bedtime. If you have to work until the last possible moment before sleep, there are several things you can do to at least avoid screen exposure:

  • Put aside an hour of work that doesn't need a computer as the last thing to do that day.
  • Put your reading on an e-Ink screen. Unlike LED's or LCDs, e-Ink screens don't emit light. Like print, they reflect the light in your room.

The worst thing you can do is use your electronic devices in bed. Not only are you making it harder for yourself to fall asleep, you're probably not being productive anyway. It's bad hygiene. You wouldn't eat in bed because it's gross. The same goes for working in bed.

I found that the reason that I couldn't stop looking at screens was because I planned my day poorly. When I didn't get enough work done in the day, I would stubbornly stay up, staring at my outline, trying to squeeze out work from the late hours at night. I eventually learned it is better to admit defeat when my day is over and let myself get rested for the next one.

Change the Hue on your Computer using f.lux

For people who work on computers, f.lux is a freely available software that changes the colors on your screen to warmer temperatures and reducing the amount of blue in your display. You might feel like your display looks weirdly orange at first, but your eyes quickly adjust.

Install f.lux

The f.lux homepage also lists a ton of research related to light exposure and sleep. You can follow the makers of f.lux at @justgetflux@herf, and @lorna.

Change the Lights at Home

If you really want to go hard against blue light, it may also be worth checking the lights in your bedroom. Fluorescent lights tend to be blue but you can find lights with warmer hues. For the particularly ambitious, amber lights are readily available as an alternative to the regular tones, and they allow little blue light.

Color temperature comparison of common electric lamps. From Wikipedia:  http://en.wikipedia.org/wiki/Color_temperature#Color_temperature_applications

Color temperature comparison of common electric lamps. From Wikipedia: http://en.wikipedia.org/wiki/Color_temperature#Color_temperature_applications

Use Blue Light in the Morning

Getting blue light exposure during the day is much easier than avoiding blue light at night. All you need to do is go outside and spend some time in direct sunlight without sunglasses (no need to look directly at the sun).

Superman gets his power from the sun; you can too

Sunlight exposure in the morning is correlated with higher energy levels and decreased depression. For those who have trouble falling asleep, blue light exposure in the morning has been correlated with earlier sleep onset.

For those who cannot get sunlight exposure, there are artificial alternatives:

Philips produces lamps that simulate sunlight. A few function as an alarm and gradually increase in brightness, just like a sunrise. Many have reported that waking up to light is much easier and less stressful than waking up to a loud buzzer. The other alternative is the much more intense blue light.

Get a Blue Light

If you want a more direct approach to getting blue light, you can get your very own blue light. These lamps cut straight to the point: high-intensity blue light to stimulate the Melanopsin in your eyes.

The Philips goLITE BLU Energy Light. From my bed stand

The Philips goLITE BLU Energy Light. From my bed stand


I use the Philips goLITE BLU Energy Light as an alarm. It's pretty intense, and exposure to this light has a stronger awakening effect on me than coffee. After I've woken up, I set the light in my kitchen as I make breakfast to continue exposure. It only takes 15-30 minutes for the light to have an effect.