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Do blue light blocking glasses actually work?

They claim to help stop headaches and keep us from staying up too late, but are they worth the money?

Angela Lang/CNET

I've been staring at screens my entire life, from my parent's early Gateway machine, to Macintosh desktops at school, to my iPhone, iPad and MacBook today. I'm obviously not the only one.

The average office worker spends 1,700 hours per year(!) in front of a computer screen. And that's just while we're at the office -- we're also addicted to using our phones all day long.

All of that screen time seems to come with various ill effects on our bodies and minds, such as eye strain, headaches and insomnia. To combat those problems, you can pick up a pair of computer glasses -- also called blue-light blocking glasses -- which promise everything from eliminating eye strain to helping you sleep better.

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Once hard to find, there are now plenty of stylish options from companies like Felix Gray and Peepers. You can even get blue-light blocking lenses for your prescription glasses.

So do blue-light blocking glasses really make a difference for all of us who stare at a screen 8-plus hours per day? The answer isn't as straightforward as yes or no.

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Is staring at a screen for hours each day bad?

The short answer? Probably.

Doctors and researchers are largely focused on two issues that arise from our ever-growing screen time: Digital eye strain and blue light exposure.

According to the American Optometric Association, digital eye strain is "a group of eye- and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use." Those issues range from blurry vision and dry eyes, to headaches and neck pain.

By staring at screens all day, we're also exposed to blue light waves, which are said to cause a myriad of issues. There is conflicting evidence about how blue light exposure affects your eyes, but doctors and researches are in agreement that it does affect your circadian rhythm. More on that below.

What is blue light?

All visible light we humans see contains the entire spectrum of the rainbow, from red to violet. Within that spectrum are blue light waves, which are said to help us stay alert and upbeat.

What gives off blue light?

Any source of visible light gives off blue light waves, whether it's the sun, a touchscreen or a light bulb.

We get plenty of blue light waves each day from the sun, but after dark we're still exposed to it from many artificial sources.

How does blue light affect sleep?

When the sun goes down, the lack of light signals our bodies to start producing melatonin, the hormone responsible for making us fall asleep.

Before the advent of artificial light, the sun regulated our sleep schedules. But today, we're exposed to light all day and into the night. While exposure to any light waves after dark delays our bodies' production of melatonin, blue light waves can be especially problematic because they keep us alert.

On the other hand, blue light can help us overcome sleep issues by disrupting our usual circadian rhythm. The Lumos mask, for example, uses light therapy to mitigate the affects of jet lag.

So, what does my phone or computer screen have to do with this?

Compared to fluorescent and incandescent bulbs, LEDs can give off a significant amount of blue light.

Unfortunately for all of us who cozy up to our tech after sunset, LEDs are used in countless smartphone, tablet and TV screens. Tech products that have a LCD screen, like laptops, iPads ($175 at Amazon) and older iPhones, still use LEDs to backlight their displays.

Is blue light harmful?

Blue light has been linked to all sorts of issues, from causing digital eye strain to making us blind. There's a lot of conflicting evidence, however, about exactly how harmful (or not) it really is.

The American Academy of Ophthalmology says that there's no evidence that the blue light specifically given off by screens will cause eye damage, as we are exposed to blue light all day from the sun.


Peeper's blue-light blocking glasses.

Angela Lang/CNET

Talking to CNET, Dr. Raj Maturi, a clinical spokesperson for the American Academy of Ophthalmology, explained, "During the day, you get 10 times as much blue light from the sun as you do from your computer screen. Our bodies have evolved to deal with this light."

However, research compiled by the AOA indicates that prolonged exposure to blue light (such as sitting in front of a computer all day) might cause damage to your retina -- the innermost layer of your eye that sends signals to your brain to process what you are seeing.

Prevent Blindness, a nonprofit dedicated to mitigating vision loss, also says that early research suggests that blue light can contribute to eye strain.

What are blue-light blocking glasses?

Blue-light blocking glasses have filters in their lenses that block or absorb blue light, and in some cases UV light, from getting through. That means if you use these glasses when looking at a screen, especially after dark, they can help reduce exposure to blue light waves that can keep you awake.

Many blue-light blocking glasses you can buy also claim to help reduce eye strain.

Most are meant to be worn during the day while working in front of a computer, and at night to prevent the blue light from screens from keeping us awake.

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Should I get blue-light blocking glasses?

It depends -- do you want or need to look at your phone after dark, and having trouble falling asleep?

There is ample evidence that blue light affects when our bodies create melatonin, so if you use screens long after sundown, these glasses might help stop you from staying up later than you want.

If you deal with digital eye strain, however, there is a easy exercise you should try before you invest in new glasses. Use the 20-20-20 rule: every 20 minutes, look at something at least 20 feet away for 20 seconds. 

The idea is that this helps break your focus from your screen, allowing your eye muscles to relax and stave off eye strain.

As for me, I'm writing this article wearing a pair of blue-light blocking glasses that I've used off and on for the last few months. While I'm not 100 percent certain that they are helping my eyes, I do notice my eyes feel less tired at the end of the day.

Could it be a placebo? Sure. But I'll keep wearing them to find out.

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The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.