That Neuroscience Guy - Neuroscience Bites - Blue Light

Episode Date: July 27, 2022

You've probably been warned about the potential of too much "Blue Light" being harmful, especially for sleep. In today's Neuroscience Bite, we discuss why and how Blue Light actually affects your brain activity. 

Hi, my name is Olof Krogolsen and I'm a neuroscientist at the University of Victoria. And in my spare time, I'm that neuroscience guy. Welcome to another Neuroscience Byte. The other day I had to go to the optometrist. I'd slowly realized that I need reading glasses, and sure enough, after a decade of avoiding the optometrist, it was confirmed. For the first time in my life, I have to wear glasses. And the part that's interesting is that when I was getting the prescription set up, the technician asked me if I wanted to have blue light filters on my lenses. And I know that blue light's a big deal. We've all heard about the impact of blue light on our lives

but I really started thinking about it and going, well, what's going on in the brain? Like what does blue light do to the brain and why would you want filters on your glasses? Well, light is part of the electromagnetic spectrum and each different wavelength of light is associated with a different color. So blue is unique in that

sense. It's got its own specific wavelength and that's what makes it blue, just as the other colors do as well. But what's special about blue light in the brain? Well, blue light has both positive and negative impacts on the brain. Blue light when you're awake actually helps keep you alert. There's been studies that show that blue light wavelengths during daylight hours boost attention, they decrease reaction times, and they even have a positive impact on mood. So the blue light that you get from your electronics devices, say your iPad or your Kindle, at least a Kindle Fire, say your iPad or your Kindle, at least a Kindle Fire, it has a positive impact. So you can almost argue in some obscure way that being on your iPhone or your iPad during the day is good for you.

It's going to help you focus and decrease your reaction times. It might even make you happy. But that's not where we typically associate the problem. Most of the time, the idea of blue light is that it's bad for us in terms of sleep. And the research is pretty clear on this. Exposing yourself to screens when you're trying to get ready for bed has a negative impact on sleep. We've known that for some time. So staring at your iPad screen right when you're getting ready to call it a night, well, it actually keeps you awake. And the question is, why? What is the impact of blue light on the brain? Well, quite simply,

what blue light does is it suppresses the release of melatonin. And melatonin, when released naturally, helps your body prepare for sleep. It basically, it sort of governs the circadian rhythm that puts you in that mode where it's going to prepare the body for a decent sleep. So when you're staring at your iPad right before bed, you're actually not releasing enough melatonin. And because of that, you're basically not going to sleep well or have trouble sleeping. What's interesting with this as well, that this blue light exposure late at night has also been linked to diabetes, potentially heart disease and obesity. So there's a lot of reason not to stare at those screens before you go to bed.

Anyway, that's a little bit about the impact of blue light on the brain, the positive side when you're awake during the day, but also the negative side at night. I hope you enjoyed this neuroscience bite. Remember, if you've got ideas for episodes, just DM me on Twitter at ThatNeurosci guy, or you can email us thatneuroscienceguy at gmail.com. And also check out the website. We've got our Etsy store where we're selling some shirts, and we've got Patreon where you can support the podcast directly and the grad students in my lab. And of course, thanks for subscribing to the podcast. And if you haven't yet, please do. My name's Olof Kregolsen, and I'm that neuroscience guy.

I'll see you on Sunday for another full episode of the podcast.