Do Blue-Light-Filtering Glasses Work?
Three pairs of glasses, two weeks, one goal: to find out whether blue-light-blocking lenses could actually make me sleep and feel better
Get full access to Outside Learn, our online education hub featuring in-depth fitness, nutrition, and adventure courses and more than 2,000 instructional videos when you sign up for Outside+.
Confession: I spend most of my day staring at glowing rectangles. Even at a publication like Outside, staffers are inside a lot of the time, typing and swiping away.
And those screens emit blue wavelengths of light. We want this blue light during the day: it keeps us awake and alert. But prolonged exposure to it, especially at night, has shown to mess with our sleep patterns. “When the sun goes down, our body is expecting to have darkness, to prepare for sleep,” says Lisa Ostrin, assistant professor at the University of Houston’s College of Optometry. Exposure to blue light decreases the production of melatonin, the sleep hormone in our body. “It releases when it’s dark and helps prepare our body for sleep,” she says. “Now we have all this artificial light while we’re looking into our devices, and it’s telling our bodies that it’s still daytime and we should be awake.”
This epidemic—some would say paranoia—has led to a whole industry of companies trying to prevent screen users from getting overexposed. You can find desktop apps like F.lux, which decrease the blue light from your monitor as it gets darker outside, or physical screen covers, such as Purp’s, which block blue light from your smartphone. For iPhone owners, the built-in night-shift function decreases the device’s blue-light production.
Then there are companies like Felix Gray, Zenni, and Gunnar, among others, that have developed eyewear designed to filter out blue light. The brands say that their lens technologies—like special polymers and filtering solutions built into the lenses and tinted coatings—block blue light.
These brands also claim that their glasses combat digital eyestrain—one of the effects of staring at screens for long periods of time. Symptoms include headaches, dry eyes, and general irritation. The American Optometric Association has coined this computer vision syndrome. But Ostrin disputes that blue light itself contributes to the problem of eyestrain. There’s “no direct evidence that blue light from digital devices causes damage to your eyes,” Ostrin says. Still, the act of staring at screens for upward of ten hours every day felt problematic any way I approached it, and I wanted to keep my eyes healthy.
I was both intrigued by and skeptical of these glasses. I’d been searching for a solution to the headaches that kicked in after long days in front of a screen (which usually resulted in me gulping down more coffee, providing a temporary fix until the caffeine buzz wore off) and the worry that watching Netflix before bed was frying my eyes and keeping me awake. So I decided to review three pairs in hopes that my test would provide answers to two questions: Will my eyes feel any differently after wearing the shades? And can they help me get better, or at least more, sleep?
The studies are promising. In 2017, Ostrin and her team conducted one to see if blue-light-blocking glasses affected sleep. She had subjects wear the glasses for two weeks from about 8 P.M. until they went to bed. “We measured their melatonin levels at nighttime and in the morning, before and after they wore the glasses at night,” Ostrin says. After two weeks, she and her team found that the subjects’ nighttime melatonin levels had increased by about 58 percent. “Which is huge,” she says. “We also found that our subjects, on average, slept for an extra 24 minutes. Subjectively, all of the subjects—every single one—said they slept better and woke up feeling more rested.”
Additionally, a 2009 study at the University of Toledo found that adults who wore amber lenses that blocked blue light had significantly better sleep over three weeks.
For my own two-week experiment, I tested nonprescription blue-light-blocking glasses from the three brands I mentioned before—Felix Gray, Zenni, and Gunnar—and recorded how I felt. (After seeing a few Instagram ads for these glasses, I did some research and picked these brands since they had a considerable amount of positive customer reviews.) For five days during the week, I wore a pair of blue-light-blocking glasses while at my office computer and then from 5 P.M. until bedtime, which was whenever I felt sleepy. I tried to wear each pair for the same amount of time each week, and I changed frames daily. For the two other days of the week, I left the glasses off and shut down any blue-light-reducing apps on my screens.
The three companies don’t share a standard blue-light-blocking rating, so my subjective take on how much blue light they blocked was measured two ways: how harsh my screen (at full brightness) felt on my eyes and my energy levels after a session of screen time with the glasses on.
With the glasses on, I noticed some immediate differences: the light from my screens didn’t look as harsh, my buzzing headaches became less frequent, and my eyes didn’t feel zapped at the end of the day. While the glasses had varying levels of blue-blocking intensity, I noticed the biggest changes with Gunnar’s darker, more yellow-tinted lenses.
Gunnar Mod Glasses ($100)
In my opinion, the Gunnar glasses have the strongest filter of the three, thanks to the custom tint and the lens coating, which softened the look of any light-emitting devices and cut down on screen glare, respectively. If you’re a night owl or often work late, I recommend you try these. Since I tested the Mods with an amber lens tint, everything in view did appear more yellow. Gunnar does offer different lens tints (as well as prescription options) if you don’t want to distort the color of the images on your screen.
Zenni Blokz Blue Blocker Lenses ($25 and up)
The Zennis, which have a blue-light-absorbing polymer, are handy for checking e-mail in the morning when you don’t need as much blocking power and want a lighter option. But at night, the Zennis were not as effective as the Felix Grays or Gunnars. The light from my screens still penetrated through, and I felt awake even as I was trying to wind down. Still, at $25, they’re an affordable option for easygoing blue-light protection. Zenni also offers a wide selection of prescription frames if you’re looking to add the technology to your everyday glasses.
Felix Gray Nash Glasses ($95)
Out of the three, Felix Gray’s glasses were the Goldilocks option. The company bakes a blue-light-filtering solution into each of its frames to prevent any blue-light-filtering coating from wearing off or chipping. The frames are also coated with anti-glare protection, which I found effective when staring at bright screens. I’d choose these for workday wear, not too early in the morning and not too late at night. In terms of fit, they were the most comfortable—sometimes I forgot I had them on. Like Gunnar and Zenni, Felix Gray offers prescription frames for daily wear.
As for sleep, rarely did I lie awake in bed trying to count sheep. Every night during the two weeks—with the glasses on and off—I was asleep within 15 minutes of turning out the lights. I didn’t notice any huge changes to my sleep quality, despite the experiences of Ostrin’s test subjects. On average I didn’t feel more rested on the mornings after I’d worn the glasses the night before. And the glasses didn’t necessarily make me sharper or work more efficiently throughout the day.
My eyes felt better with them on, though. And during the periods without the glasses, my headaches crept back, and I found myself heading to bed an hour later each night, on average, compared to days when I wore the glasses.
For context, I called my local optometrist here in Santa Fe, Dwight Thibodeaux. It turns out he sees even less of an impact from blue-light glasses: “They have no effect on my sleep patterns,” he says. He told me that this blue-light-blocking technology will work wonders for some and zilch for others. “Some people are more excitable,” he said, meaning they have a stronger reaction to blue light and may benefit more from its absence than someone who isn’t as susceptible, “but these glasses don’t have a huge impact on eye health.”
Despite Thibodeaux’s suggestion that blue-light-blocking glasses can be hit-or-miss, he still recommends giving them a try in case you’re one of those people for whom they may work. Ostrin advises wearing the glasses, too. “You might hear a lot of suggestions to turn off all your electronic devices an hour or two before bedtime,” Ostrin says. “So the glasses are kind of a way to get around that and still use your devices and be productive.”
Perhaps what’s most telling is that I’m still using all three glasses after weeks after testing.