When Do We Need to Actually Block Blue Light
Do blue light glasses work to protect your eyes from digital screens?
In recent years, we've become more aware of the blue light from screens bombarding our eyeballs. Maybe your parents told you that watching too much TV would rot your brain or turn you into a couch potato.
Well, rotten brains and couch-potatoes aside, let's take a serious look at blue light. Is it actually harmful? And if so, do blue light glasses work to address it?
What Is Blue Light and Where Does It Come From?
Common sources of blue light include the sun, fluorescent lighting, LED lighting, and digital devices like computers and smartphones. You see, visible light comes in a spectrum of wavelengths. Each wavelength has its own energy level, and blue light actually has the highest energy of any wavelength on the visible spectrum.
Because of that, blue light has the potential to impact your eye health more than other types of visible light. Digital screens of all kinds — computers, smartphones, televisions, tablets — emit lots of this high-energy blue light.
But Is Blue Light Harmful?
Because of all that blue light, it makes logical sense that spending a lot of time on digital devices could potentially lead to eye strain. However, studies into the potential harm caused by blue light haven't been too conclusive. Research is ongoing, but there have been mixed results thus far.
Blue Light and In Vitro Injury to Ocular Surface Cells
A 2019 in vitro study (meaning the study was conducted in an artificial environment, not done on actual people), researchers concluded that blue light injured human ocular surface cells, and that a shade could protect those cells. But this recommendation was theoretical, as living human beings were not used in the study.
Blue Light and Cataracts — Rats! (Literally)
In 2020, a study of rats revealed a correlation between increased blue light exposure and development of cataracts. But as you know, people — with a handful of exceptions — are not rats.
The Experts Weigh In on Blue Light
While the American Academy of Ophthalmology recognizes digital eye strain, it stops short of asserting that blue light causes eye damage or adversely affects eye health. See the following excerpts from a 2021 article published on the AAO website:
"Long hours staring at digital screens leads to decreased blinking. Blinking less sometimes causes a series of temporary eye symptoms known as eye strain . But these effects are caused by how people use their screens, not by anything coming from the screens. The best way to avoid eye strain is to take breaks from the screen frequently.
"The American Academy of Ophthalmology does not recommend blue light-blocking glasses because of the lack of scientific evidence that blue light is damaging to the eyes."
In short, there are other factors in play that may be contributing to your eye strain. To put it plainly, your discomfort probably isn't caused by the blue light itself, but by effects like decreased blinking. You should also keep in mind that experiencing eye strain isn't the same thing as having eye disease.
Passing symptoms of eye strain aside, the big unanswered question is this:
Does blue light actually damage your eyes?
While it's often asserted online and in the media that it does, this assumption isn't necessarily backed up by real data.
The Bigger Issue of Eye Strain
According to data from DataReportal published in March 2022, the average American spends 7 hours and 4 minutes in front of a screen every day.
If you've felt like your eyes were bugging you after hours in front of a computer or other screen, you may have experienced digital eye strain. Digital eye strain is also known as computer vision syndrome, or CVS.
VisionCenter.org estimates that 90% of people who use digital devices experience symptoms of digital eye strain, including:
- Pain in the shoulders, back, or neck
- Trouble focusing between near and far
- Discomfort or strain in the eyes
- Difficulty keeping eyes open
- Increased light sensitivity
- Trouble concentrating
- Headaches
- Blurred vision
- Double vision
- Reduced blinking
- Dry eyes
- Eye fatigue
- Eye redness
- Tearing
- Itchy eyes
The severity of your symptoms will depend largely on how long you've been using the digital device. Underlying eye conditions will also have an effect, as will other factors such as glare on the screen from overhead lights.
Fortunately, the symptoms of digital eye strain or computer vision syndrome are usually temporary, and will soon subside when you stop using your devices. Sometimes, it's possible for symptoms to continue for a while after that.
Other Factors Contributing to Digital Eye Strain
Pay attention to your eye movements the next time you're using a computer or other digital device. You'll probably notice that your eyes spend a lot of time shifting focus.
Maybe you're looking for a piece of code. You could be hunting in the virtual distance for the next zombie. Or maybe you're scrolling social media posts for the ones that you actually want to read. That's a lot of work for your eyes.
Adding to those demands is the glare caused by ambient lighting, or the contrast on your computer screen.
Plus, when your eyes are focused on something closer to you, like a screen, smartphone, or book, your pupils tend to contract and become strained. On the other hand, pupils tend to relax when looking at things further away.
Many factors — shifting focus, glare, contrast, infrequent blinking, and closeness — can easily lead to the symptoms of digital eye strain listed above. Sure, your eyes may be irritated after a long day on the computer, but that doesn't mean blue light is the real culprit. Maybe you just need a break.
What Are Blue Light Glasses?
So if we aren't sure that blue light actually damages your eyes, what does that say about the effectiveness of blue light glasses?
Blue light blocking glasses (sometimes called computer glasses) are just what they sound like. They're glasses made with special blue light lenses designed to filter out blue light, but let other types of light through.
The idea is to protect your eyes from the high-energy blue wavelengths, reducing the potential for eye damage from prolonged exposure. Now that you know what blue light glasses are, let's talk about whether they actually work.
What the Science Says About Blue Light Glasses
Research released in February of 2021 indicates that blue light lenses may have no effect at all against eye strain symptoms. 120 eye-strain-symptomatic computer users were asked to complete a 2-hour computer task. Each person was randomly given either clear (placebo) glasses or blue blockers, but each was led to believe they were wearing blue blockers.
After 2 hours, there was no significant difference in the feedback given from each group. Even more telling is that there was no difference in the eye strain symptom score between the two groups. In short, the blue light glasses had no effect.
Add this study to the fact that blue light may not even be the real culprit for your digital eye strain, and there are serious doubts about the effectiveness of blue light blocking glasses.
Mixed Reviews and Ongoing Research
A 2017 study of 80 computer users found that after one month of using lenses coated with a blue blocking coating, one-third felt they received benefit. They claimed that the glasses improved vision and reduced glare while they used digital screens.
It should be pointed out that this study was funded by a maker of blue light glasses.
Other studies are currently underway, like this one which intends to take a closer look at whether blue light lenses provide users with any definitive benefit.
Blue Light Glasses and Sleep Quality
While The American Academy of Ophthalmology doesn't state that blue light is damaging to the eyes, there are many people who say wearing blue blockers in the evenings helps them sleep better.
Maybe it has to do with circadian rhythm or simply reducing harsh stimuli before heading for bed. Whatever the reason, some data seems to suggest that blue light blocking lenses may have sleep-related benefits in some people. But let's take a closer look at those studies.
Blue Blockers, Bipolar Patients, and Sleep Quality
A 2020 study randomized 20 hospitalized bipolar patients in a manic state, with some wearing clear glasses and others wearing blue blocking glasses for 7 days. During that time, their motor activity, sleep, and wakefulness patterns were monitored. After 5 nights, the blue blocker group experienced significantly better sleep efficiency and less wakefulness after getting to sleep.
These findings suggest that blue blocking glasses may help hospitalized manic patients sleep better. However, the sample size of the study was small, and no baseline data was gathered before the study.
Athletes, Blue Light, and Falling Asleep
In a 2019 study, 15 healthy athletes were instructed to wear either blue blocking or transparent glasses for 3 hours before going to bed. Their sleep was monitored for 9 nights in a row, and they were given a set of guidelines to follow for their nighttime routine. While blocking the short-wavelength blue light was "mainly effective" in shortening the time it took them to get to sleep, there was no impact on total sleep time or wakefulness after they got to sleep.
Blue Light's Effect on Melatonin in Healthy Adults
In 2011, a small study of a handful of healthy adults measured nighttime melatonin levels under varying conditions. The conditions included 2 hours of being blindfolded, then 90 minutes of exposure to various irradiance blue LED lamps, white fluorescent lamps, and followed by 90 minutes of additional blindfold time. In this study, melatonin concentration was found to be suppressed significantly with some blue light irradiances. However, actual sleep quality was not assessed.
The evidence that blue light significantly suppresses melatonin levels could mean that in theory, wearing blue blockers may help you sleep better at night. However, that doesn't mean you should rely on them to prevent eye strain, especially when there are other reliable ways to do this.
In 2019, another study of blue light filtering glasses provided subjectively better sleep when worn in the evening, but researchers couldn't verify this with objective measurements of sleep parameters.
How to Protect Your Eyes From Potentially Harmful Light
Some people experience eye strain, dryness, headaches, even nausea and other symptoms due to photophobia, or abnormal light sensitivity. For them, certain types of light (particularly blue) can lead to debilitating pain, migraine attacks, and major disruptions to normal life.
If this sounds like you, blue light glasses probably won't be much help. You need light sensitivity glasses specifically designed for people with photophobia.
Wear Light Sensitivity Glasses
Light sensitivity glasses made by Axon Optics have been shown to reduce symptoms of photophobia, such as migraine. Their precision-tinted lenses folder out only the specific wavelengths of light known to pose the most risk, letting the rest in. They're available in prescription and non-prescription with indoor and outdoor lenses.
Axon Optics photophobia glasses, also called migraine glasses, have been studied extensively and shown effective against light sensitivity symptoms like migraine. In a clinically-validated HIT-6 (headache impact test) survey, here are just some of the results that were found.
- 85% experienced a decrease in headache impact
- 33% fewer headache days
- 40% decrease in light sensitivity impact
- 85% of users reported decreased light sensitivity
If your digital eye strain is due to photophobia, light sensitivity glasses are a much better choice than blue light blocking glasses. On that note, here's an amusing but true story.
We recently heard from a customer asking about returning a pair of our glasses. She had ordered her daughter a pair late last year, which she wears all the time for her remote computer job. The glasses were so helpful that they ordered a spare pair a few months later.
After wearing the "second pair" of glasses several times, the daughter reported that they didn't have any effect. Thinking they might be defective, her mom asked about a return. Later, however, she came back to report that the ineffective pair her daughter had tried were actually NOT Axon Optics glasses, but a pair of blue light blocking glasses they'd purchased before buying anything from Axon.
That's a true story that illustrates the difference between the benefits of light sensitivity glasses and the unproven benefits of blue light glasses!
Take a Break, Would Ya?
As if you needed another excuse to catch a break, simply giving your eyes a few seconds of relief now and then can go a long way to reducing eye strain. Many experts recommend the 20-20-20 rule. That is, every 20 minutes, focus your eyes on something about 20 feet away for 20 seconds. It can relax your eyes and give them a much needed "time out."
Use Artificial Tears
A little lubrication for your eyes can go a long way to preventing the dryness and irritation you might otherwise be dealing with.
Sit Properly
As we talked about earlier, the close proximity of your screen to your eyes can be a contributing factor to eye strain. Try sitting further back from your computer. Aim for about 25 inches, or arm's length. It might also help to position your chair or desk so you look slightly downward at your screen.
And like your parents probably cautioned you as a teenager, stop slouching! Neck, back, shoulder pain could be a result of poor posture. So stay upright and look at your screen with your eyes, not your head or neck. A periodic stretch and a few backward shoulder rolls might help, too.
Summing It All Up
When it comes to easing digital eye strain, the best thing you can do may be to practice good habits, take frequent breaks, and see your doctor if you feel you're more sensitive to light than normal.
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Source: https://www.axonoptics.com/do-blue-light-glasses-work-a-science-based-analysis/
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