Experiment: Is Blue Light Special?

I’m almost two weeks into a sleep related experiment. As someone who has had insomnia as long as I can remember, I’ve tried most “here is how to sleep better” claims. Nearly all of them have met with failure on a personal, n=1, level. This is a new one which is backed up with real scientific study. What is it? Managing your blue light exposure.

Before getting to my results to date, we should explore the premise behind the experiment. Specifically, the hypothesis is our circadian rhythm is disrupted, or potentially largely regulated, by exposure to blue wavelength light.

The Circadian Rhythm (CR) is the daily cycle we humans (and other organisms) exhibit. For more details, see the Circadian Rhythm Wikipedia Entry. To summarize, this is the rhythm that triggers your body’s natural sleep responses and activities. You could think of it as your body clock. Say, for example, the CR triggers your body’s sleep hormones at 9PM. If you alter the timing of your body clock such that the hormones are not produced until midnight, you won’t get sleepy until then, or at the least have a hard time getting to sleep.

With that out of the way, how can or how does blue light affect your body clock? Some of the research I’ve seen on blue light specifically dates back to around 2007. However, a more recent study on blue light does a fairly good job in explaining the details.

Circadian rhythms are responsive to external stimuli, called “zeitgebers”. One well known example of this is normally called “jet lag” - the adjustment you need to make when crossing time zones in a short time. What happens is as your time zone changes, especially if you cross multiple zones, the timing of the light hitting your body is different in relation to the human created clock. Thus your body has to re-synchronize, and in that time period you don’t match the time zone. Studies have been finding that blue light is a significant zeitgeber.

Exposure to blue light triggers wakefulness and alertness, increasing ability to sleep and trigger non-sleep hormones, delaying sleep hormone production. If we put these factors together we can see a reasonable hypothesis that blue light exposure after the sun sets may well delay the production of melatonin making it more difficult to get to sleep and decrease the likelihood of deep and restful sleep. Now, on to the parameters of the experiment.


First, the rules:

  1. No electric lights, including screens, after 9PM.
  2. Candles out by 11PM.

These may seem pretty simple, and as such they are. The best results are more often from simple rules. On the other and, as an insomniac I can assure you this can sound distressing. You see, for me what most often keeps me up is a sudden shift in my brain from tracking my surroundings to “oh, we can now think of all the cool stuff we like to think about!”

Historically, I’ve ‘treated’ this by getting up and recording it. Usually typing it in at the computer or on my iPad. But this often leads to increasing the thought process, especially if it is something fascinating or exciting. As to why this happens, the studies on blue light affecting concentration and wakefulness play a role in explaining it. I get up to write, expose myself to a bright screen with plenty of blue and BAM!, fully awake.

On a sidenote, as I read more of these studies I had the realization that there have been times in my life when I do’t have problems sleep and sleeping well - even getting up at the crack of dawn. They’ve all been when I’ve gone camping or for other reasons am sleeping away from electric lights. Between these realizations and the evidence I decided this was worth it.

So after nearly two weeks what has happened? Quite a bit, it seems.

My first night was like any other regular night for me, simple sans electric lights and with some candles. I was able to fall asleep by 0200-0230 - earlier than of late but not great. However, my body did decide it wanted to awaken around 7AM (normally that happens around 10AM). But that twoo does occasionally happen. The next night was the first surprise. At around 10PM I was sleepy. I was asleep by midnight. I continued to awaken around 7AM.

This kept up through Friday morning, a full 5 days later. I then decided to let the weekend happen. By Saturday morning I had “lost” all of the week’s progress. Resuming Sunday night I repeated the previous week’s experience. The rest of the week, including this Saturday morning I was able to sleep much better and my body would awaken around 7-8 AM depending on when exactly I fell asleep. In most nights I’ve been asleep before midnight - a tremendous change for one used to 4AM.

As to my nighttime idea generation, it still occurs. It does so earlier in the evening, however, and writing it down using a pencil, paper, and candlelight seems to prevent the impetus to keep working things through. The latest I’ve seen on my bedside clock this week was one-thirty in the morning. Yet I still awoke the next day around 7.

It has only been a day short of two weeks, and I took a couple days off in the middle, but so far it seems to be working. If it continues to do so, this could be a longer term change.

Bill Anderson avatar
About Bill Anderson
Just your frendly neighborhood curmudgeon!