Spending long hours in front of a computer screen or devouring Netflix every night is a daily habit for many of us. And if you believe the hype, the blue light emitted by our electronic devices is robbing us of sleep and causing an epidemic of digital eye strain.
Step into the blue light blocking glasses, which claim to repair our sleep and relieve the symptoms of tired and sore eyes for good. But do they work? We are looking at the evidence.
Experts are not concerned about environmental exposure to blue light, including that emitted by screens.
What is blue light and is it harmful?
Blue light is part of the electromagnetic spectrum, and most of the exposure we get to it comes from sunlight. It is also artificially emitted by our digital devices and LED bulbs.
As blue light is close to UV light in the spectrum – and we know the risks UV light poses to the skin and eyes – it has been the subject of many studies, says Dr Nisha Sachdev, ophthalmologist and director. from the Australian Society of Ophthalmologists. .
“However, I don’t think there is any evidence to suggest that normal environmental exposure to blue light, including that emitted by digital screens, causes measurable damage to our eyesight,” she says.
Optometry Australia optometrist Luke Arundel agrees. “The level of blue light exposure from computer screens and mobile devices is lower than that absorbed when you go out in natural sunlight – and is below international safety limits,” he said. . “So at this point, we don’t have to worry about computers or phones being ‘blind’ our eyes.”
Can blue light cause digital eye strain?
This is a question worth asking, given that digital eye strain is said to affect millions of people around the world.
In the United States alone, a 2016 survey found that 65% of adult respondents reported symptoms of digital eye strain – which typically includes dry, itchy eyes, blurred vision, and headaches resulting from prolonged use. computers or other devices. But experts doubt the blue light is to blame.
“We are a very digital society and this screen addiction is a relatively new phenomenon over the past 5-10 years,” says Dr Sachdev. “And indeed, this year, with everyone working from home, I have seen many patients showing symptoms of digital eye strain.
This year, with everyone working from home, I have seen many patients showing symptoms of digital eye strain.
Dr Nisha Sachdev, ophthalmologist and director of the Australian Society of Ophthalmologists
“However, I think the eye problems we see more and more are not so much about blue light but more about spending hours on digital devices and blinking less, which affects lubrication. eye. Wearing contact lenses for more than the recommended eight hours in one session also doesn’t help. “
Arundel adds that there have been few smaller studies and anecdotal evidence linking blue light to eye strain.
“Researchers have shown that high intensities of blue light can damage retinal cells, but the majority of this research has been carried out in laboratories or in animal models,” he explains.
“More evidence is needed on whether exposure to blue light specifically causes eye strain and research is ongoing in this area.”
Blue light can impact your sleep / wake cycle.
What about the links between blue light and sleep?
There have been a number of studies on the effects of exposure to blue light at night from lights or LED screens, including that it can interfere with melatonin production, which may have an impact on the sleep / wake cycles.
However, it is not known whether this causes adverse health effects, and it continues to be researched, according to the Australian Agency for Radiation Protection and Nuclear Safety (ARPANSA).
“Good sleep is the result of several factors and is not only influenced by the blue light coming from the use of the screen,” explains Arundel.
“But limiting blue light exposure by reducing screen brightness, using nighttime apps like F.Lux and Apple Nightshift, and turning off devices at least an hour before bed are highly recommended for good night’s sleep.”
What are blue light blocking glasses?
Glasses blocking blue light have special coatings that filter out the blue light emitted by electronic devices such as televisions, computer monitors, tablets and smartphones. Some of these devices, such as smartphones and tablets, have built-in blue light filters that you can “turn on” that claim to do the same.
Glasses or blue-blocking lenses are regularly touted by eyewear makers to help combat digital eye strain – and anecdotal evidence is mixed. Some consumers say they don’t help much, but in a 2015 CHOICE report on blue light blocking glasses, some trials said that after using the glasses, they ‘probably’ or ‘maybe’ slept. better.
Do glasses really work?
If you use blue light blocking glasses to combat digital eye strain, there is currently little high level evidence that they work for this purpose. Current lenses can block 6% to 43% of blue light, but blocking all blue light during the day could have other negative effects.
“Blue light, the greatest source of which is the sun, naturally suppresses the body’s production of melatonin, which tells our body to wake up,” says Arundel.
“Blue light is beneficial during the day because it stimulates attention, reaction times and mood – it’s actually essential for our overall health and well-being, so block out all blue light during the day. may negatively affect your body clock or circadian rhythms. “
Blue light is beneficial during the day because it stimulates attention, reaction times and mood
Dr Luke Arundel, Optometrist, Optometry Australia
What about the night port? Well, a 2017 University of Houston study found that participants who wore the glasses three hours before bed while using digital devices or watching TV experienced a 58% increase in their rate of nocturnal melatonin. However, this was a small study of 22 people.
Further studies have been carried out to determine whether glasses blocking blue light have other health benefits, adds Dr Sachdev.
“These were small studies, and overall there was a lack of evidence to support the use of blue-blocking lenses to improve visual performance, relieve eye strain, or maintain health. macular.
“A 2018 study suggested that wearing blue light-blocking glasses for an hour before bed can improve sleep quality and relieve symptoms of insomnia, but that would also be tantamount to not having digital time for an hour before going to sleep. “
Book a comprehensive eye exam before investing in blue light blocking glasses.
Do blue light glasses help with headaches and migraines?
If you suffer from headaches or migraines after long hours of staring at a computer, it makes sense to wonder if the blue light is to blame. But is it?
“There is no evidence that glasses blocking blue light will help prevent headaches or migraines,” says Dr Sachdev.
“A migraine is more likely to be made worse by the brightness of your screen or because you don’t take regular breaks than exposure to blue light.”
Arundel agrees that there are many factors that can contribute to eye strain or headaches, which should be ruled out before investing in blue blocking filters.
“A comprehensive eye exam with an optometrist will examine your focusing system, whether you need corrective lenses, your eye coordination, and whether you have dry eye syndrome.”
Are blue light blocking goggles good for night driving?
If you have issues with driving at night, this is a different issue than using blue light shields to filter blue light from screens.
“At night, there’s more contrast in the light, so we’re really talking about contrast sensitivity here,” says Dr Sachdev, “and there’s no evidence that blue light-blocking glasses will help drive the light. night.
“In general, we find that there is often an organic cause for difficulty driving at night, like cataracts, that people don’t realize. So if you have difficulty driving at night, you need to. a complete eye exam to decide to eliminate any problems that could be the cause. “
Where to get blue light blocking glasses
Want to try blue light blocking glasses anyway? You can buy blue blocking lenses from optometrists – Oscar Wylee will add a blue light blocking filter to any of his frames for $ 80, while OPSM’s BlueGuard lenses will set you back $ 50 on top of the lenses. selected.
Just be aware that there is currently no specific Australian standard for blue light filtering glasses or screen protectors, according to the Royal Australian and New Zealand College of Ophthalmologists (RANZCO).
Other ways to reduce eye strain
We struggled to lift weights in the gym for hours, but we expect our eye muscles to function flawlessly without interruption under extreme workloads, Arundel explains.
“Even for someone with perfect vision, the eye muscles will become sore, fatigued, and fatigued from ‘overuse’,” he explains.
“A good habit to adopt to avoid this is the 20/20 rule, where every 20 minutes you have to look up and away for 20 seconds to give your eye muscles a break.”
Dr Sachdev also recommends staying hydrated, using lubricating eye drops, and lowering your screen brightness.
“I have done this myself on all my devices as well as my clinic computers – and it really helps,” she says.