If you’ve been shopping for eyewear recently, you might have picked up on the latest trend: Glasses with lenses that block blue light.
In a world full of computer, tablet and smartphone screens, health concerns like eyestrain and insomnia have been blamed on blue light from electronic displays. By filtering out blue light, eyewear makers claim that these new lenses can reduce eye fatigue, help you sleep better and more.
But are blue-light-blocking glasses worth the marketing hype?
We’ll take a quick look at the science behind both the lens technology and the claims. We’ll also check out other, more effective solutions to relax your eyes and improve your sleep. While there may be truth to the features of blue-light-blocking glasses, their benefits might not be enough to justify their extra cost.
How we see light: Sunlight, blue light, bright light, screen light
Every day, the sun delivers electromagnetic radiation to earth with energy waves of all kinds, including radio waves, gamma rays and microwaves. We can’t see many of these waves with our eyes, except for those delivered with wavelengths between 400-700 nanometers (nm). Combined together, these waves produce white light. Separate those into their specific wavelengths and you can see a literal rainbow of color covering what’s called the visible light spectrum – red at the high end of 700 nm, then orange, yellow, green, cyan and blue to violet at 400 nm.
Just above violet light is blue light with wavelengths between 400-500 nm. In the visible spectrum, it’s the light that has the second lowest wavelength but nearly the highest punch of energy. Every day, the sun transmits loads of blue light to earth. A delivery that our bodies (and eyes) have welcomed over millennia. However, the past few decades have delivered another mass producer of blue light – the light-emitting diode (LED) screen.
Smaller, lighter, brighter, more vivid and more efficient than the cathode-ray tube (CRT) displays of the past, LED screens are the electronic display of choice in the vast majority of today’s gadgets. But those crisp colors and lower energy appetites also come with a heavier dose of blue light. Today’s LED displays emit blue light at a range of 430-500 nm with an intense spike at 455 nm. And as eyestrain and sleeplessness from screen use continues to rise, so do questions about the effect of blue light on our bodies.
Is blue light dangerous?
No, blue light by itself isn’t bad for your eyes, you brain or your body. Having exposure to blue light won’t give your eyes short- or long-term damage, or cause disease. All in all, research has proven that when it comes to humans and our bodies, blue light is pretty harmless.
However, there are definitely links between heavy screen time and eyestrain. There is also scientific evidence linking in-bed screen time with the inability to both fall asleep and get sufficient rest. While it may not be toxic, does blue light still have a hand in causing these problems? If so, some believe that blue-light-blocking lenses are the solution.
The what and how of blue-light-blocking glasses
Blue-light-blocking glasses, blue-light-filtering lenses, computer glasses or BluBlockers (the originals from 1986), all share the same feature and benefit combo: tinting or technology that filters out a percentage of blue light to your eye, reducing eyestrain and improving your sleep.
If you need prescription eyewear, you can usually add blue light filtering to your lenses for an average of around $25-$75 extra depending on where you get your glasses. Without a prescription, you can pick up a pair of blue-light-blocking glasses, frames and lenses included, starting at around $20 upward to $100. These kinds of lenses and glasses are usually covered by vision insurance and HSA reimbursement, but it’s a good idea to check with your plan ahead of time to see if that’s the case for you.
The technology behind blue-light-filtering lenses
Blue-light-blocking lenses tend to work in one of two ways. The first is the original 1980s approach created by BluBlockers – fashionable, amber-tinted lenses that are ideal for filtering out 100% of visible blue light. Unfortunately, these lenses also have the disadvantage of coloring everything with shades of yellow.
Fortunately, technology has caught up to provide a second method. Today’s blue-light-filtering lenses filter out 20-25% of 455 nm blue light while preserving the rest of the visible spectrum. This way, other colors stay crisp, including blue tones, without the more intense waves of blue light hitting your eye. Lenses that block out higher percentages (around 41-45% of 455 nm blue light) are also available, but this higher degree of protection results in lenses that have a slight tint.
Does the research back up the blue-light-blocking claims?
Blue-light-blocking glasses are excellent at filtering out blue light, no question. Commercially available blue-light-filtering lenses do a great job of blunting the brightest and harshest blue light while providing enough balance of true color to the rest of the rainbow. The claimed benefits and protection of blue-light-blocking glasses come from 20-25% filtering, according to eyewear makers.
However, even though blue-light-filtering glasses work, do they deliver on the claims of better health – namely, better eye health and better sleep health?
The biggest benefit that blue-light-filtering eyewear makers claim is that the reduction of blue light reduces eyestrain and damage. To date, there is no research directly linking the presence or abundance of blue light to any kind of human eye condition. While research is ongoing, there is really no evidence saying that reducing blue light to your eyes is beneficial in any way.
So why do our eyes hurt after using a computer or smartphone screen? There are several reasons: outdated prescription glasses, bad posture, dry eyes, screen distance and lack of blinking are just a few on a long list of causes. However, that list doesn’t include blue light exposure. Blue light won’t cause short- or long-term damage on its own.
Blue-light filters and their effect on sleep health
Can we get better sleep health through less exposure to blue light? As humans, we’ve been getting heavy doses of blue light from the sun for all of our history. So much so that our bodies have evolved to take our sleep cues from the sun. When the sun is up, our bodies respond by being alert and awake. When the sun is down, the absence of light kicks internal processes into gear like melatonin production, making us drowsy and ready for sleep. Every new day, this pattern repeats – a 24-hour sleep-wake cycle called the circadian cycle or circadian rhythm.
An Aug. 2019 study in the Journal of Biophotonics found that blue light is linked as the primary signal for our bodies to wake or start drifting to sleep. This study also illustrated how usage of screens that produce blue light (like computer and smartphone LED screens) are throwing our bodies out of sync with our circadian rhythms. Exposure to blue light is causing our bodies to think that they’re still being exposed to daylight. As a result, our bodies don’t start the mechanisms to ease into sleep until after the source of the blue light is shut off.
That means that your late night TikTok binge is actually keeping you awake rather than lulling you to sleep. Makers of blue-light-blocking eyewear claim their lenses make it possible for you to scroll and surf into the early hours while still getting a good night’s sleep once you’re finished. But the research doesn’t prove this either. While there are developing links between blue light exposure and circadian rhythm disruption, there’s zero proof that blue-light-filtering glasses have any positive or negative effect on the process. The only real solution researchers see, at least for now, is to shut off the source of the blue light, not just filter it out.
Are blue-light-filtering glasses safe to use?
Yes. Even though the research doesn’t seem to back up a lot of health benefit claims about blue-light-blocking glasses, there also isn’t any evidence of negative effects from either short-term or long-term use. So while there may not be any advantages, there also aren’t any disadvantages either. It all comes down to personal preference and whether or not you want to spend money on something you don’t really need.
Better, cheaper ways to get results
In short, when it comes to the claims of better eye and sleep health behind blue-light-blocking glasses, the evidence isn’t quite there. But that doesn’t mean that there aren’t proven, less expensive solutions. With a new habit or two, you should be seeing and sleeping better soon.
If your eyes feel dry, gummy or strained while using your computer, tablet or smartphone, there are a few things you can do to get relief without having to throw on a new pair of specs:
- Take more breaks – It’s all about keeping a healthy balance of screen time for both you and your family. Just a few minutes away from your screen every hour gives your eyes some well-needed rest. Quick breaks are also great excuses to get up and drink some water or get in some quick exercise. If you’re too busy to get away from your screen, follow the “20-20-20” rule – every 20 minutes, look at an object at least 20 feet away for at least 20 seconds.
- Don’t forget to blink – It sounds silly, but it’s easy to forget when we use computers and smartphones. According to the American Academy of Ophthalmology, studies show that humans blink only 5-7 times a minute while using digital devices instead of the normal blink rate of 15 times a minute. Blinking is essential in keeping your eyes fresh and comfortable – make sure to move your eyelids regularly or use artificial tears to keep your eyes from feeling dry.
- Lighten up – When working from home, if you like to type in the dark with a hyper-glowing screen, you may want to rethink your setup. Your eyes need to work harder to adjust and focus on an object that is brighter than its surrounding environment. Instead, increase the light around you, bump down your screen’s brightness and increase your screen’s contrast.
- Keep your distance – The ideal distance between you and your screen should be about 25 inches. If you don’t have a tape measure handy, here’s an easy tip. If you throw your arm out and your computer screen either bashes into your wrist or is well beyond the tips of your fingers, you should adjust accordingly. Also, as you’re sitting, check to see that your eyes have to look slightly downward to see your screen – having to look up or straight ahead can strain your neck. Speaking of, give your sitting posture a good evaluation as well. Slouching or craning your neck is a good indication that your setup needs a refresh.
Fall asleep faster
The only clear way to preserve your sleep rhythm at night is to put down your smartphone or close your laptop. Any source of blue light, however filtered, is still going to affect your ability to fall asleep. The key is to shut down your devices one to two hours before you need to fall asleep.
However, that doesn’t mean you can’t use other methods to relax your brain before bed. Reading a book or doing a crossword by the light of your nightstand lamp can give you something relaxing to do that doesn’t involve blue light. Or you can listen to a podcast, audio book or white noise before drifting off. Just make sure you don’t give in to the temptation of checking your email before choosing your selection for the evening.
Getting help when blue light may not be the problem
If the above tips aren’t helping to relieve your dry eyes or reduce your eyestrain, talk with one of our eye care doctors and vision specialists. During an eye exam, your eye care expert will discuss your symptoms, look for a cause, then create a treatment plan to help you feel better.
If you need help falling asleep, making an appointment with a primary care doctor is a good first step. Chronic sleeplessness can have many causes, so a visit to a primary care doctor can help narrow them down. Your doctor can help determine why you’re having problems and create a plan that will help improve your ability to fall and stay asleep.