For many people who struggle with insomnia and sleep, blue light is often a huge concern. They worry that exposure to blue light, such as through the TV or phone, can interfere with their sleep. Consequently, they avoid blue light like the plague.
But is blue light really something to be feared?
Overall, the research suggests that there can be a relationship between blue light exposure and impacting our circadian rhythm. For example, light exposure in the evening can sometimes push our bedtimes into a little later at night.
However, the research tends to be a little overstated and requires a fair amount of nuance. Let’s get into this a little more deeply.
Issues with the research on blue light and sleep
There are a number of limitations with the research on blue light and sleep. Most studies investigating this relationship tends to be limited in sample size and done in an artificial setting. For example, having participants stare at a bright light for hours. Consequently, the results of these studies may not be very applicable to real life situations.
As well, there’s a fair amount of research that may have never been published because they did not find significant results. This can skew findings to make it seem like the effects of blue light on sleep are stronger than they might really be.
Special considerations about blue light
Still there are some considerations when dealing with blue light.
One of the important findings about the impact of evening light on sleep is that it depends on how much light you get during the day. It’s the relative amount of light that really impacts sleep. For example, if you have been outside during the day and got some sunlight (which can be up to 100,000 lux– lux being a measure of light intensity), the amount of light you get from a phone screen (10 lux) is very minimal by comparison.
The nugget of wisdom here is that evening light from screens is unlikely to impact sleep if you have gotten a decent amount of sunlight during the day. However, if you haven’t had a chance to get much sunlight, it is possible that the light from screens could affect your sleep and delay your rhythm. One thing I would encourage is to avoid too much light if you are awake in the middle of the night. This is because we have habituated to the darkness and the light becomes relatively stronger compared to the dead of night.
Another important factor is distance from the light. The further we are from the light source, the less impact it has on our sleep. In this case, if we are watching TV, the amount of blue light that reaches our eyes is inconsequential. But if we are putting our phone very close to our eyes, this may more impact on our sleep.
Finally, not all effects of blue light on people’s sleep is equal. If we are more of an early bird, and we go to bed usually pretty early, it may not be too big of a deal for our sleep to be slightly delayed. In some cases, it might even be preferred!
On the other hand, night owls might benefit from a longer winddown period and less exposure to evening light if they want to be able to go to bed a little earlier.
Amount of light vs content of the screen
Perhaps more important than the amount of light on the screen on our sleep is actually the content on the screen. For example, if we are reading a very exciting book on our Kindle or watching a spooky movie on Netflix, this likely will impact sleep more than the light exposure itself. We may be too interested to put the book down or too anxious after the scary movie to sleep well.
Therefore, while it’s not a terrible to use screens in the evening, I would encourage something light and relaxing – like a nice rerun of Friends or a nice book that you know you can put down.
Do’s and Don’ts of Blue Light
Here are some recommendations that may be helpful to limit the impact of screens on our sleep:
- Do try get some sunlight during the day to reduce the relative impact of screens on sleep
- Don’t use your screens to watch anything too alerting before bed
- Do try to include a winddown period and limit screen time especially if you are a night owl
- Don’t be too frightened about blue light!
Best wishes,
P
Simply mental health 