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Q&A: Should I Be Wearing Blue Light Glasses?

With an increased reliance on technology in our work, academic and personal lives, many are left wondering if their eyes are at risk from staring at a screen for long periods of time. In response, many drug stores, pharmacies and online retailers are now selling blue light glasses, designed specifically to block blue light rays that are emitted from phones, tablets and laptops.

But are these glasses necessary? Do they actually work? Blair Armstrong, MD, an ophthalmologist on staff at Jefferson Health - Abington, offers an expert opinion on the effectiveness of blue light glasses.

Q: Realistically, how long is it safe to look at a screen every day or at one time?

Dr. Armstrong: We're spending more and more time on screens every day, especially considering that we all have a mini computer in our pockets. But there isn't much data to support an optimal or dangerous amount of screen time.

Like ultraviolet (UV) rays, the major source of blue light is from the sun. The exposure that we get from televisions, computers, smartphones and other technology is insignificant compared to the amount that we get from the sun. Our eyes are exposed to more blue light from going outside and looking at the sky than from staring at our screens, despite the closer proximity to our faces.

Q: Do blue light glasses really work?

Dr. Armstrong: Blue light glasses aren’t harmful, so they won't hurt the eyes. The American Academy of Ophthalmology, however, doesn't recommend the use of blue light glasses, because there’s no real data to show their benefit or the danger in increased blue light exposure from screens.

Q: What are the short- and long-term effects of looking at a screen for an extended period of time daily?

Dr. Armstrong: There are negative effects, but it has more to do with how we're using technology than the actual blue light. Negative effects stem from eye strain when looking at a screen for a long period of time. This can present in different ways, but symptoms include irritation, teary or watery eyes and increased headaches. All of these symptoms have more to do with our blink rate, which normally decreases when we're looking at screens for an extended period of time, allowing the surface of the eye to become dry.

Q: If screen time can’t be avoided, are there other ways to mitigate side effects?

Dr. Armstrong: The best way to mitigate eye strain is to keep your eyes lubricated with artificial tears, and to give them breaks often. I always suggest the 20-20-20 rule: Every 20 minutes, take a 20-second break, and look at something 20 feet away.

Also, if you wear glasses or contacts, make sure that you’re wearing the right prescription. Looking at a computer may require a different prescription than reading glasses or driving glasses. Some people wear a trifocal with a lens for computer-distance glasses. If you’re experiencing eye strain, contact your eye doctor to see if your prescription needs to be adjusted for mid-range or computer distance.

One other thing that you can do to mitigate the effects of screen time is adjusting the brightness and contrast on your devices. When we use our devices at regular brightness at nighttime, it can trick our brains into thinking that it’s daytime and will throw off our circadian rhythm - making it difficult to fall asleep. The best thing to do is to regulate how much you use your devices before you go to bed. The “night shift” setting on devices can help to mimic the spectrum of light that occurs in nature at dusk.

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