3 Potential Benefits of Wearing Blue-Light Glasses, According to Experts
Health & Wellness
Three eye specialists explain everything you need to know about blue light and its potential impacts on eye health—and what to do about it.
It's possible you've heard about blue light and how it may pose a threat to eye health. But, what exactly is this type of light, and is it harmful to eyesight? And, is there any benefit of wearing a pair of blue-light-blocking glasses?
What Is Blue Light?
Blue light emits from digital devices—including smartphones, tablets, laptops and televisions—as well as fluorescent lights, compact fluorescent light bulbs and LED lights. However, it's important to note that the American Academy of Ophthalmology reports the biggest source of blue light comes directly from sunlight.
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Also known as high-energy visible light, blue light is part of the visible light spectrum, said Brian Boxer Wachler, MD, ophthalmologist and eye surgeon at Cedars-Sinai Medical Center in Los Angeles.
He referred to the acronym ROYGBIV—which stands for red, orange, yellow, green, blue, indigo and violet—and explained that all of these colours are on the visible light spectrum (meaning these are the portions of the electromagnetic spectrum that are visible to the human eye, as defined by NASA).
Is Blue Light Harmful to Eye Health?
Before answering this question, it's important to understand how the human eye absorbs blue light.
As the spectrum of visible light travels, the wavelengths (measured in nanometres) separate and vary in size, resulting in the different colours. The blue-light portion of the spectrum is considered to have a short wavelength, ranging from 400 to 500 nanometres, explained Tatevik Movsisyan, OD and clinical associate professor in practice at The Ohio State University College of Optometry.
"In animal studies, this [short] wavelength has been shown to be toxic to the retina or the back portion of the eye. However, to date, there is no evidence that blue light causes this type of damage to human retinas", Movsisyan said.
While research is ongoing, a scientific review—published in a 2022 issue of the journal Heliyon—stated that artificial blue light does not significantly impact ocular health. The latest information from the AAO says current evidence shows no meaningful link between blue light and damage to human retinas and age-related macular degeneration.
In fact, evidence suggests that there are benefits to blue-light exposure. For instance, a 2022 systematic review found that athletes who were exposed to blue light experienced some benefits, such as better cognitive performance, enhanced alertness and improved reaction time.
While enhanced alertness is helpful during the work day, excessive screen use before bed could disrupt sleep quality.
"The blue light from electronic devices doesn't harm your eyes, but blue light can interfere with sleep because it can disrupt melatonin secretion", Boxer Wachler said.
Melatonin is a hormone that the brain produces in response to darkness to help promote feelings of sleepiness. It also helps with the timing of the body's internal clock (circadian rhythms), as defined by the National Institutes of Health.
Jennifer Tsai, OD, explained that blue light emitted from digital devices can disrupt the body's natural circadian rhythm by tricking it into thinking it's still daytime, making it difficult to fall asleep and ultimately reducing sleep quality. (Of course, sleep schedules look different for someone who works the night shift.)
A review published in the 2019 journal Chronobiology International—which examined a link between light exposure and circadian rhythm in 15 studies—indicated that two hours of blue light exposure in the evening can suppress melatonin. And, a sports medicine review in a 2022 issue of the journal Frontiers in Physiology found that blue light could hinder both sleep quality and duration.
As screens become increasingly used in daily life, related headaches and eye strain might be on the rise, too. In fact, research indicates that adults all around the world are spending more time staring at their phones and tablets than in the past. For example, Comparitech released data confirming that, on average, people aged 16 to 64 spent a total of 6 hours and 37 minutes looking at a screen each day.
With screens being such an integral part of your day-to-day, here's what you need to know about the efficacy of blue-light glasses.
What Are Blue-Light Glasses?
Blue-light glasses—which are specifically designed to filter out any potentially harmful blue light—are said to reduce or prevent possible symptoms associated with digital screen use. Below, three eye doctors shed some light on the topic.
Possible Reasons To Wear Blue-Light Glasses
1.They May Help Promote Healthy Sleep
One of the best things you can do before bedtime is power down screens. But, wearing blue-light glasses may enable you to use screens prior to shut-eye—without sacrificing good sleep.
"The only definitive research-backed health benefit of blue-light-blocking glasses is for improving sleep", Boxer Wachler said.
In fact, a systematic review from a 2021 issue of Chronobiology International identified "substantial evidence" (from 24 publications) that blue-light-blocking glasses reduced sleep latency (the time it takes a person to drift off to sleep) among patients who experienced sleep disorders, jet lag or inconsistent work schedules.
2.They May Reduce Light Sensitivity
The artificial blue light from electronic devices could possibly lead to headaches, trouble focusing and light-sensitive eyes, Tsai said.
"Normally, we would wear sunglasses outdoors to mitigate this effect, as sunlight also emits blue light", she said. "However, indoors, our eyes are still exposed to blue light from screens, making them more light sensitive".
But, blue-light glasses may not help remedy digital eye strain. According to a randomised controlled trial, published in a 2021 issue of the American Journal of Ophthalmology, blue-light glasses didn't appear to help prevent or improve symptoms of eye strain after two hours of computer use.
"Sometimes people confuse eye strain and computer vision syndrome with blue light being the cause, but it's not", Boxer Wachler said. "The cause of those conditions is excessive time spent on electronics because any long periods of time focusing on anything up close leads the eyes to blink 30 percent less than normal".
So while blue light is not entirely responsible for digital eye strain, blue-light blockers may help with symptoms related to light sensitivity.
3.They May Decrease Symptoms of Dry Eye
Since staring at screens for hours can reduce the amount of blinking, Tsai explained that dry eye symptoms (such as redness, burning sensation or watery eyes) may surface due to a lack of tear film production.
"Wearing [glasses with] a blue light coating can help reduce glare and light sensitivity, thereby relaxing strain and sometimes improving blink rate", she said.
According to a small-scale study in a 2016 issue of the journal PloS One, adults with dry eyes who wore eyeglasses with 50-percent blue-light-blocked lenses showed improvement in visual acuity. For context, visual acuity is the clarity or sharpness of vision, per the American Optometric Association.
Tips for Buying Blue-Light Glasses
For anyone interested in wearing blue-light glasses, Tsai strongly suggested that you first consider your specific prescription eyewear needs. Then, search for a pair of blue blockers that filter the entire range of blue light from 410 to 460 nanometres. Read the details about the blockers on the packaging, but bear in mind that glasses with an orange or amber tint are designed to block more (if not all) of the blue light, compared to glasses with clear lenses.
"Bear in mind that a blue-light coating on glasses does not necessarily imply UV [ultraviolet] coating", she continued. "To ensure UV protection, make sure the lenses you purchase are equipped with it".
If you're unsure whether the glasses you've bought can block blue light, Tsai advised making an appointment with an optometrist. "We typically have spectral devices that can test the specifications", she said.
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When To Wear Blue-Light Glasses
Tsai considers blue-light blockers as optional.
"I'll explain to my patients that there certainly is no downside since these glasses can help with light sensitivity from a long day of screen time", she said.
"So if someone chooses to wear blue-light glasses, it's best to wear them whenever they're looking at any type of digital screen, which includes working on computers, scrolling on phones and reading on tablets".
Boxer concurred, citing additional tips to consider, too. Turn off the blue light from all electronics by going to "Settings", then to "Display" and finally, select night mode. "This shift removes blue light from your phone and computer. It's normal for the screen to look a little orange, but most people get used to it".
He also advised to take frequent eye breaks. "I recommend the 20–20 rule, which is for every 20 minutes of screen time, close your eyes for 20 seconds". Another variation is the 20–20–20 rule, which entails taking 20 seconds to look away from your screen, specifically looking at something about 20 feet (6 metres) off in the distance, and doing this every 20 minutes.
Movsisyan said she is strongly in favour of shutting off electronics at least one hour before bedtime, along with meeting with an eye-care provider before choosing to buy any type of glasses.
"A comprehensive exam to determine if prescription glasses are needed or if anti-reflective coating on glasses, which is known to block some of the blue light, would be beneficial", she said.
Due to the lack of evidence supporting blue blockers, the AAO does not recommend any blue-light-blocking eyewear for computer use. Be sure to talk to your eye doctor about whether or not blue-light glasses would be helpful for you.
Words by Amy Capetta