Biohacking Thursday: Improving Sleep by Avoiding Blue Light

As mentioned in a previous posting, I’ve started engaging in a series of controlled (and relatively sane) biohacking experiments.

The goal of these experiments is to use a variety of physical techniques, technological devices, or pharmaceutical interventions to alter my individual biology or psychology and thus improve my general health and wellbeing. This might involve trying cryotherapy to reduce the unremitting pain in my shoulder and knees, using biofeedback to improve my focus and mood, or eating a ketogenic diet in order to (finally) get rid of the layer of fat around middle while maintaining or increasing my lean body mass. I will be trying each of these ‘hacks’ in the not too distant future.

For this initial experiment, I explored the use of amber glasses and other blue-light blocking devices to improve the quality of my sleep.

iStock-535226519-640x427For most of my life I have been a terrible insomniac. When I was in high school and college, I was lucky if I slept more than four hours a night. Even on those nights when I could get to bed early or sleep late, my chattering mind would keep me up for hours or my traitorous body would wake up every 30 minutes or so until I finally got up.

Things have gotten better as I got older, but I still have considerable difficulty getting to sleep or staying sleep. In recent years, I’ve averaged about five to six hours a night, well below the seven or more that most sleep experts recommend.

I normally muddle through the workweek by consuming relatively large quantities of coffee and taking the occasional nap during the day. The unfortunate consequence of this approach, however, is that my general energy levels are usually quite low, which adversely affects my productivity, my workout routine, my attitude, my memory, and my waistline.

Moreover, in desperate attempts to replenish and recharge, I am sometimes forced to take extremely long naps on the weekends, which can interfere with my limited time off and seriously mess with my circadian rhythms. These long naps can also make my chronic insomnia worse; taking a two-hour nap on Sunday afternoon often means that I don’t get to bed until nearly 3 AM on Monday morning.

Over the past year, I’ve tried a number of different tricks and tips recommended by doctors, researchers, and pop-culture websites to improve my sleep. These included cutting out caffeine (which just made me grumpy and chronically tired, but still unable to sleep), avoiding alcohol (which improved my waistline but little else, particularly given my penchant for a nice ale or two), and the use of a white noise machine (which simply ended up being something for my monkey mind to latch onto as it stubbornly refuses to turn off).

One of the approaches that many followers of the primal lifestyle recommend is trying to adopt the more natural sleep cycle that our Paleolithic ancestors followed out of necessity.


In the absence of artificial lights, the underlying theory postulates, our caveman predecessors were forced to go to sleep once it got too dark to see. They also arose as soon as the sun came up, thus having a wake-sleep cycle closely attuned to diurnal and seasonal variations in light.

While there is some new data questioning whether or not humans in traditional cultures truly go to sleep shortly after sundown – a recent study of Hadza and San hunter-gatherers in Africa shows they actually go to sleep many hours later, but do sleep soundly through the night – there is compelling research demonstrating that physical exposure to light (even via the skin rather than the eyes) reduces the production of melatonin and other sleep-inducing hormones. This makes sense given that human beings, as diurnal (i.e. active during the day) creatures, should be stimulated awake while the sun is up. As soon as the sun (and our light exposure) goes down, however, melatonin production increases and we rapidly tire.

More importantly, the type of light that seem to have the strongest effect on sleep is blue light; exposure to wavelengths from the higher end of the visible spectrum (blue, indigo and violet light) directly suppress melatonin production, both making it harder to fall sleep and making it take longer to go to sleep.

man-working-on-computer-in-the-darkAs it turns out, our modern electronic devices (televisions, smartphones, tablets, laptops, and e-readers) produce large amounts of blue light. These devices use light-emitting diode (LED) back-light technology to help enhance screen brightness and clarity, but these LEDs produce very strong blue light waves.

Spending even a couple of minutes each night watching TV, checking emails, or sending a text appears to be enough to disrupt our normal circadian rhythms and diminish the duration and quality of our sleep.

To test this hypothesis systematically as part of my biohacking project, I tried the following experiment:

For two weeks I carefully tracked my sleep patterns using the old-school approach of recording when I went to bed, each time I noticeably woke up, and the total duration and quality of my sleep using a paper journal. For the following two weeks, I then scrupulously avoided blue light after sundown and similarly tracked my sleep patterns.

I reduced my blue light exposure at night by:

  1. Reducing the total amount of time watching television, using the computer, or checking my smartphone after dark (instead I got a lot of reading done, making a significant dent in the large pile of books on my nightstand);
  2. Using a problem called f.lux to adjust my computer screen throughout the day, reducing the amount of blue light produced early in the morning
    and late in the afternoon so as to mimic the natural change in exposure;
  3. Setting the ‘night shift’ function on my smartphone to significantly reduce the amount of blue light produced; andprospek-computer-glasses-blue-light
  4. Wearing amber glasses from the time the sun went down until I went to bed to further eliminate any blue light exposure (i.e. the few times I did watch TV or check emails, I did so while sporting some rather nifty amber sunglasses).

As limited as these data are – two control and two experimental weeks with a total subject number (or ‘N’) of one – the results were pretty impressive.

Week 1 (Control): The median (average) number of hours I slept each night was 5.8 hours (mean of 5.9 hours), with a range of 4.7 to 6.3 hours. I also woke up an average of 3 times a night, for 10 to 15 minutes each time. Subjectively, the quality of my sleep was mediocre to poor.

Week 2 (Control): The median number of hours I slept each night was slightly better at 5.9 (mean = 5.8), with a range of 5.1 to 6.9 hours. I still woke up an average of 3 times a night, for 10 to 15 minutes each time. Subjectively, the quality of my sleep was mediocre.

Week 3 (Experimental): The number of hours I slept each night was significantly better than in the previous two weeks. The median was 6.4 (mean = 6.4), with a range of 5.7 to 7.3 hours. I also woke up less during the night, averaging only 1 noticeable disturbance. The quality of sleep also seemed better, and I woke up feeling relatively refreshed.

Week 4 (Experimental): I slept an average of 6.9 hours a night (mean = 6.8), with a range of 6.5 to 7.3 hours. Moreover, for the first time in a while I actually slept completely through the night. Not only did I wake up feeling refreshed, I also noticed improved energy and mood throughout the day. I also seemed to fall asleep faster, often zonking out as soon as my head hit the pillow.

While I still plan to explore additional ‘hacks’ to improve my sleep, including the use of herbs like ashwaganda and schisandra or spending 20 minutes in an infrared sauna each evening before bed, the simply trick of avoiding blue light proved to be a very effective approach to combating my chronic insomnia.

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