All colors of light have the potential to cause retinal injury depending on the intensity and duration of exposure, says Raymond Iezzi, MD, an ophthalmologist at the Mayo Clinic in Rochester, Minnesota. But blue light—the primary type of light emitted from LED-based devices like your computer and smartphone—has a shorter wavelength than other colors of light, and it delivers more energy to the eye compared to softer (think: red or yellow) sources.
"Individuals tend to blink less frequently when mesmerized by what is on their screens, or by simply focusing on their work for extended periods," explains Dr. Iezzi. "This can worsen symptoms of dry eye and cause burning, irritation, and blurred vision."
What's more, studies suggest that the blue light given off by our favorite devices also suppresses melatonin production, which can throw off our circadian rhythms—and ability to fall asleep at a reasonable hour—as a result.
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Many experts recommend powering down your electronic devices a few hours before bedtime to give your eyes a much-needed rest. But if you do need to look at your screens in the evening, is it worth wearing blue light-blocking glasses?
A new study by researchers at the University of Houston College of Optometry published in the journal Ophthalmic & Physiological Optics found that while the blue light emitted from digital devices could be contributing the high prevalence of reported sleep dysfunction, participants who wore short wavelength-blocking glasses three hours before bedtime for two weeks experienced a 58% increase in their evening melatonin levels. They also reported sleeping better, falling asleep faster, and staying asleep for longer.
Whether blue light-blocking glasses actually work to prevent digital eyestrain has not been confirmed. "No scientific studies have established their value with regard to eye health," says Dr. Iezzi. Still, "any eyeglass that has a yellow or brown tint will filter some blue light."
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The bottom line: Blue light-blocking glasses aren't going to reverse the effects of all that screen time on your peepers. But they might help you fall asleep faster the next time you stay up late to meet a work deadline or finish a Keeping Up With the Kardashians marathon (no judgment). Here, three blue light-blocking glasses to wear while you’re plugged in at night.
