As digital spaces have become one of the main ways we communicate with each other, it’s no wonder the amount of time Canadians spend on their screens has been on the rise. Consequently, many of us have become more aware of how devices are impacting our eyes—and what we can do about it. Enter blue light glasses.
Fatigue, eyestrain and headaches are all symptoms of computer vision syndrome, a condition that results from prolonged screentime. Non-prescription blue light glasses (or the blue light coating that’s available for prescription lenses) purportedly combat the negative impact screens can have on our eyes. But are they really worth buying? We asked two experts to weigh in.
Okay, back up—what is blue light, and what does it do to your eyes?
Blue light is part of the spectrum of light our eyes are exposed to on a daily basis. “We get a ton of blue light from the sun, it’s a natural light that we all actually need to function,” says Mahnia Madan, an optometrist based in Vancouver.
Blue wavelengths cause alertness and help regulate our circadian rhythm: the internal clock that lets us know when it’s time to sleep or wake up. “At night, when the sun sets, the blue light in the environment goes down and tells our bodies that it’s time to rest. And in the morning when we wake up with blue light in the environment, it triggers our body to be alert,” she explains.
But the blue light that comes from our screens—specifically the LED lights used in TVs, computers and smartphones—can mess with this natural cycle. “LED light over-represents blue light,” says Melissa Yuen, an optometrist based in Toronto. Blue light suppresses the body’s release of melatonin, a hormone that makes us sleepy. During the day, this can increase cognitive performance and keep us alert, but research suggests that being exposed to blue light before bedtime can impact sleep quality.
What are blue light glasses?
Blue light glasses, also known as blue light–blocking glasses, have specialty lenses with a reflective coating that helps to filter out blue light from your device (instead, you’ll see a yellowish tinge).
The hued lenses have risen in popularity over the past few years, thanks to marketing that touts their ability to improve sleep and prevent digital eyestrain.
So, do they work?
Studies suggest that using blue light glasses before bed can help those who have trouble falling asleep, and anecdotally, Madan says some patients find the glasses’ yellowish filter more comfortable when looking at a screen. But despite their popularity, the efficacy of blue light glasses in combatting the symptoms of computer vision syndrome is up for debate. “There still isn’t any great deal of scientific evidence that [they] protect us from computer vision syndrome or any harmful kind of light from the computer,” explains Madan.
A 2021 article from the American Academy of Ophthalmology says there is no evidence that light from screens is what causes digital eyestrain in the first place. Instead, it cites other possible factors, like decreased blinking caused by long periods of screentime.
And while they’ve been shown to help with sleep, screens can affect sleep for a variety of reasons, so don’t feel like investing in these specialty lenses is the only viable solution. Instead, experts like Madan recommend limiting your screen time before bed.
How can I combat digital eyestrain?
“A blue light filter in itself isn’t going to make a big difference,” says Madan. “It’s more important that patients wear the correct prescription so that they’re able to see clearly on the computer, and so that they’re not over-focusing or under focusing, because that can cause a lot of strain.”
Yuen agrees that ensuring your prescription lenses, if you wear them, are up to date is the best way to alleviate eyestrain. She also emphasizes the importance of taking intermittent breaks when looking at a screen. She refers to the 20-20-20 rule: every 20 minutes of screen time, look into the distance at least 20 feet away for 20 seconds. “A big reason why people get eyestrain is that they are staring at a screen all day,” she explains, adding that this exercise relaxes the eye muscles.
Other common tips to avoid eyestrain include blinking often to hydrate your eyes, adjusting the brightness to a comfortable level and taking breaks from your device throughout the day. Madan adds that optimizing computer ergonomics—like using a bigger screen and font, sitting in a comfortable chair and making sure the screen is not too high or low—can also help.
Originally published on April 1, 2022. Updated on May 4, 2023.