Blue Light Glasses: What They Are and What They Do

Words by Sara Harowitz

Photography by Amy Flak

Remember when “computer” used to be a one-hour class we had to take in school? Or when cellphones were bricks we used for texting study-period winky faces to our crushes?

Yeah, neither do we.

These days, we are bombarded with screens. Between working on a laptop, FaceTiming and Instagramming on a smartphone, and streaming shows on a TV, we have been rewired to accept the constant stimulation of screen time as commonplace.

Of course, that doesn’t necessarily mean it’s good for us. Screens give off a lot of potentially damaging blue light, which is why more and more people are embracing the idea of wearing blue light-blocking glasses when they’re working or even rewatching episodes of New Girl.

“The biggest, most intense source of blue light comes from the sun, but blue light also comes from any white light source, especially computer screens, smart phones, TVs, and LEDs. A lot of those do have a really high blue output compared to other waves of light,” says Dr. Vanessa Flak, an optometrist at Vancouver Block Optometrists, via phone. “We care about blue light more than other types of light because it sits at the high-energy end of the visible spectrum of light, which is right next to UV light. And because we know that UV light is damaging to our eyes over time, it suggests that high-energy blue light might also be a risk factor for eye disease.”

What are blue light glasses?

“The whole purpose of blue light-blocking lenses is to do just that: basically block out a portion of the blue light from getting through the lens and into your eyes,” Flak says. Because we spend so much time looking at screens, a concern is that over time, this exposure could lead to larger issues.

Of course, there are many factors that could play into someone’s development of an eye problem—a disease called macular degeneration that affects vision is the main one that optometrists worry about—including diet, overall health, use of cigarettes, and family history. “It makes it hard to determine if blue light exposure is a risk factor over time,” Flak explains. “It’s an ongoing area of research.”

Do blue light glasses work?

A 2020 report published by the American Academy of Ophthalmology states that “blue light from computers will not lead to eye disease,” and a 2017 study by Ophthalmic Physiological Optics concluded something similar. But as Flak mentions, this is still being studied. As well, there are other potential advantages to using these lenses; a randomized trial published by the National Library of Medicine back in 2009 concluded that “blocking blue light could create a form of physiologic darkness. Because the timing and quantity of light and darkness both affect sleep, evening use of amber lenses to block blue light might affect sleep quality.”

Flak does see the sleep aspect as one area that people could potentially benefit from in the shorter term. “The blue light is a signal to our brains that it’s daytime, like we’re outside in the sun,” she says. “When the sun goes down, our blue light exposure should go way down, which says to our brains that it’s time for bed. Being on a computer or your phone or watching TV in the evening could make it more difficult to fall asleep, and blue light-blocking lenses can help with that for people who have difficulty falling asleep.”

On an even more basic level, blue light glasses may simply make the act of staring at screens all day a little more comfortable. “We do know for sure that blue light scatters in our eye a lot more than other longer wavelength lights,” Flak says, explaining that because a computer screen emits lots of blue light, the extra scatter can basically increase symptoms of strain—which might explain why so many of us feel like our eyes are tired and achy after a long day at work. Thus by blocking blue light, the lenses could help decrease these symptoms.

Where to buy blue light glasses

Blue light lenses are becoming more and more common, and as such are probably sold at your favourite eyewear store—and could likely be added to your glasses for a fairly minimal cost. Here are a few places to start:

If you’re thinking about getting blue light glasses, Flak suggests making an appointment with an optometrist to see if a prescription might be useful as well; she thinks that most of us with good eyesight could benefit from even a small amount of lens aid when looking at screens. “A little bit of lens power can help take a bit of strain off of the eye focusing-system and help the eyes work better together,” she explains. After all, our eyes do a lot for us. They deserve all the help they can get.