Is Blue Light Harmful to Your Health?

The digital world has created one inevitability: we all spend a lot more time in front of screens, whether it’s your computer, phone, or tablet-like device. While you could argue the dangers and downsides of what it does to your attention span, there’s a more direct issue worthy of your attention — is all of the blue light from those screens bad for your health?

In particular, does blue light damage your eyes, disrupt your sleep, or, possibly, something worse?

There’s quite a bit of misunderstanding about the origins, utility, value, and danger that blue light poses, and this episode clears the confusion and demystifies the true dangers.

In this episode of That’s Healthy, Right?, we explain the benefits (yes, benefits) of blue light and its effects on the human body, the importance of your circadian rhythms and melatonin production, a warning about wearing blue light glasses, and the 20/20/20 rule for healthy vision.

Have a question you want to be considered for the show? To submit a question, email a voice recording that you can do here to

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Solving Sleep Problems: Non-obvious Solutions to Better Rest and Recovery — Born Fitness

The effect of blue‐light blocking spectacle lenses on visual performance, macular health and the sleep‐wake cycle: a systematic review of the literature — OPO

A double-blind test of blue-blocking filters on symptoms of digital eye strain — Work 

Effects of Blue Light on the Circadian System and Eye Physiology — Molecular Vision 

LED’s and Blue Light — ANSES

Research progress about the effect and prevention of blue light on eyes — International Journal of Ophthalmology 

The Sun, UV lights, and your eyes — American Academy of Ophthalmology 

Blue Light From Light-Emitting Diodes Elicits a Dose-Dependent Suppression of Melatonin in Humans — Journal of Applied Physiology 

Effects of the Emitted Light Spectrum of Liquid Crystal Displays on Light-Induced Retinal Photoreceptor Cell Damage — International Journal of Molecular Sciences 

Cones Support Alignment to an Inconsistent World by Suppressing Mouse Circadian Responses to the Blue Colors Associated with Twilight — Current Biology 

Bigger, Brighter, Bluer-Better? Current light-emitting devices – adverse sleep properties and preventative strategies — Public Health


Adam Bornstein: I think we’re going to have our first ever That’s Healthy, Right? confession. And that is, I don’t think I’ve been to an eye doctor in probably five years. And when I say five years, I probably mean 10 years.

And I’m bringing this up because my wife has recently become concerned about my vision. I’m not sure if she thinks I can’t see, or she’s just worried because I spend so much time in front of the computer each and every day, to the point that she asked me if I’m doing any damage to my eyes.

And like any health problem, I typically go to research first before I go to a doctor. Not saying that I have any issue with doctors, they know far more than I do when it comes to health, but I like to become informed to know if I’m putting myself at risk.

And this led me down a pretty big rabbit hole when it came down to blue light, which is the light that is emitted by computer screens and other screens, like phones and tablets. And what I found so interesting once I started digging, is that a lot of us know, or think we know that blue light is causing a whole bunch of different problems, such as making it harder for us to fall asleep.

But what I certainly didn’t know and was very interested to find out, is that a lot of people completely misunderstand the utility value and danger of blue light and specifically the blue light that comes from our screens.

So, in particular, blue light actually can be a good thing. It is a necessity and the most powerful blue light comes from the sun. And the amount of blue light that we get from our screens is actually pretty minimum.

So much so that there really isn’t much evidence to suggest that it is hurting your eyes. I’m going to touch on that more in a moment, but a lot of people believe that these screens are doing damage to your eyes, and it has nothing to do, it appears with the blue light itself.

Now, if you were to stare directly into the sun for many hours a day – like we do our computer screens – that would be a different thing. But our eye has done a really good job of evolving to build a filter out a lot of the harmful rays that come in to protect ourselves from things like phones and tablets and screens and computers.

But that doesn’t mean that the blue light isn’t causing any damage. And specifically the damage we’re talking about is how it affects your sleep.

So what happens is, blue light is really important because it affects your circadian rhythm, which is when you want to go to sleep. When you want to stay awake. And if you disrupt your circadian rhythm, you can also disrupt the production of melatonin, which is known as your sleep hormone, which can make you feel really, really tired during the day, low on energy, and make it very difficult to fall asleep at night.

So the whole idea of turning off your screens before bed is accurate if you are concerned about falling asleep. And I’m going to bring this all full circle because the conversation about me needing to see a doctor was this suggestion that maybe I should be wearing blue light glasses during the day.

Now, technically those blue light glasses are going to help you because they will fill out that blue light, but there’s a big, big caveat, and a concern. If you wear them all throughout the day, you might actually have a negative impact on your circadian rhythm, something known as entrainment.

And what happens is that if you are blocking out all the blue light during the course of the day from your screens, and really from anything else, because you’re wearing your glasses, you start to wonder, when is it daytime and when is it nighttime? Because that is biofeedback. That is a signal to your brain saying, Oh, it is daytime or it is nighttime.

So, if you wear blue light glasses all day long, it actually might make it harder for you to fall asleep and completely disrupt your circadian rhythm, which is defeating the purpose. So if you’re going to wear them, wear them at night time, or just turn off the screen completely.

And if you’re worried about your eyesight, computers might cause an issue, but not from the blue light. It’s from eyestrain and dry eyes. Because apparently when you look at computers for too long, we blink less.

And the less that we blink, the less hydration and moisture we get to the eye. And that can cause a lot of issues and a lot of strain, especially if you’re looking at a computer in a dark room with your bright screen.

So, if you want to protect the health of your eyes, because you spend so much time in front of your screen, as I do, there’s a rule that people suggest, the 20, 20, 20 rule. This is what a lot of ophthalmologists will suggest, which is to try to take a 20-second break every 20 minutes and look about 20 feet away. So looking away will obviously reduce that strain. 

You should blink a little bit more. You can throw some drops in your eyes if you want, and that should help reduce the strain.

So, bottom line, you can use those blue light glasses, but do it at night. You don’t have to worry about the computer straining your eyes if you are blinking and following that 20, 20, 20 rule. And I should probably go and see an eye doctor.