What Is Blue Light
Sunlight contains many types of coloured light , each with a different wavelength and energy level. Combined, this spectrum of coloured light rays creates what we call white light .
Blue light is just one type of coloured within this light spectrum generally defined as visible light. This means that it has a short wavelength and high energy levels. Levels of blue light are emitted from a range of different light sources, the largest being the sun, which is where we get most of our exposure to it. However, there are also many man-made sources, and in recent years, blue light has gained notoriety because of its link to digital screens. Computers, tablets, smartphones and other digital screens all emit blue light. Although this is only a fraction of that emitted by the sun, however the amount of time people spend using these devices and the proximity of these screens to the eyes has caused some concern about potential long-term effects of blue light on eye health.
Adults Who Have Trouble Sleeping Can Benefit
The role blue light plays on human sleep patterns is well established, so experts say a pair of blue-light-blocking glasses can help adults snooze better. The best way to achieve a better nights rest is by using blue-light-blocking glasses at night and reducing screen brightness and exposure before bedtime. Those things definitely make a difference, said Winter. Even a dimmer switch for your home can help. As for both daytime and evening use, our experts said the science is still out on whether wearing blue-light-blocking glasses all day will be beneficial or detrimental to long-term health.
Blue-light glasses may even help you sleep better if you have limited vision or a complete loss of sight, though its best to consult your doctor. For some, these glasses could help improve sleep, Winter noted, because blue light can still affect how some people with color blindness secrete melatonin. Similarly, people who are blind can experience significant disruptions to their sleep because the light pathway in the eye is still absorbing blue light, even though the visual pathway cant see it.
Why Is Blue Light A Concern
The real issue with blue light, aside from the amount of exposure we have, is that we are exposed without protection, and we need that protection because blue light penetrates our eyes.
All visible light penetrates our eyes, passing through the cornea, through the lens, and going directly back to the retina and macula. That means, if damaging light rays pass through to the macula and retina, theres potential for damage.
We already protect our eyes from UV rays. Sunglasses shield our eyes from glare but also offer UV protection. This means your sunglasses filter out harmful UV light so that it doesn’t make it to your retina.
Your sunglasses do not protect your eyes from penetration by blue light unless they are specifically designed to do so. That means blue light is getting a free pass to your retina every time you open your phone, walk outside, turn on your computer, or do just about anything in your normal daily life.
Daytime Or Nighttime Use
Different blue light blocking lenses are recommended for use at different times of the day. Artificial blue light may contribute to digital eye strain and affect your sleep cycle, explains Dr. Hernandez. Since your body still needs to be exposed to blue light during the daytime hours to preserve your circadian rhythm, clear or yellow lenses are better for daytime use, says Dr. Hernandez.
If youre struggling with insomnia or using your laptop or smartphone late into the evening hours, on the other hand, you may want to choose darker lenses. Red lenses actually block 100% of blue light along with nearly all green and violet light, which means they block all varieties of light that may be disruptive to your sleep cycle and may help you fall asleep faster if you wear them a few hours before bedtime.
The Experts Weigh In On Blue Light
While the American Academy of Ophthalmology recognizes digital eye strain, it stops short of asserting that blue light causes eye damage or adversely affects eye health. See the following excerpts from a 2021 article published on the AAO website:
Long hours staring at digital screens leads to decreased blinking. Blinking less sometimes causes a series of temporary eye symptoms known as eye strain. But these effects are caused by how people use their screens, not by anything coming from the screens. The best way to avoid eye strain is to take breaks from the screen frequently.
The American Academy of Ophthalmology does not recommend blue light-blocking glasses because of the lack of scientific evidence that blue light is damaging to the eyes.
In short, there are other factors in play that may be contributing to your eye strain. To put it plainly, your discomfort probably isnt caused by the blue light itself, but by effects like decreased blinking. You should also keep in mind that experiencing eye strain isnt the same thing as having eye disease.
Passing symptoms of eye strain aside, the big unanswered question is this:
Does blue light actually damage your eyes?
While its often asserted online and in the media that it does, this assumption isnt necessarily backed up by real data.
How To Ease Digital Eye Strain
At CorneaCare we believe that your eyesight is a vital part of your overall health and wellbeing. You may have realized the benefits of using a standing desk or a special chair to help with back pain while you work. Taking care of your eyes while working in front of a screen is just as important to your physical health. If you can minimize the effects of digital eye strain, you may notice your work productivity increases, you sleep better, and you feel less run down at the end of the day.
Do Blue Light Glasses Really Work
If youve ever worried about the effect of digital screens on your eyes, then you may have heard about blue light, and perhaps even searched for ways to protect your eyes against it. Blue light glasses are becoming more popular than ever due to claims that they can protect your eyes against potential damage but how effective are they at keeping your eyes healthy? Here, well take a closer look into the scientific research behind blue light glasses, and whether they actually work.
Have you been thinking about investing in blue light glasses? At Specsavers, we now offer a blue light filter as part of our UltraClear, SuperClean lens treatment
Do Blue Light Glasses Work Everything You Need To Know
Benj Edwards is an Associate Editor for How-To Geek. For over 15 years, he has written about technology and tech history for sites such as The Atlantic, Fast Company, PCMag, PCWorld, Macworld, Ars Technica, and Wired. In 2005, he created Vintage Computing and Gaming, a blog devoted to tech history. He also created The Culture of Tech podcast and regularly contributes to the Retronauts retrogaming podcast. Read more…
If youve shopped for a new pair of prescription glasses lately, youve probably seen pitches for blue-blocking lenses that supposedly cut down on eye strain and reduce sleep disruptions that come from using digital screens. But do they live up to the hype? Lets take a look.
Can Blue Light Cause Digital Eye Strain
It’s a question worth asking, given digital eye strain is thought to affect millions of people globally.
In the US alone, a 2016 survey found 65% of adult respondents reported symptoms of digital eye strain which typically includes dry, irritated eyes, blurred vision and headaches resulting from prolonged use of computers or other devices. But experts are sceptical that blue light is to blame.
“We’re a very digital society and this reliance on screens is a relatively new phenomenon in the last 510 years,” says Dr Sachdev. “And indeed, this year with everyone working from home, I’ve seen many patients present with symptoms of digital eye strain.
This year with everyone working from home, I’ve seen many patients present with symptoms of digital eye strain
Dr Nisha Sachdev, ophthalmologist and director at the Australian Society of Ophthalmologists
“However, I think that the ocular issues we’re increasingly seeing are not so much related to blue light but rather to spending hours on digital devices and not blinking as much, which affects lubrication of the eye. Wearing contact lenses for more than the recommended eight hours in one session doesn’t help either.”
Arundel adds that there have been limited 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 conducted in laboratories or on animal models,” he explains.
Do Blue Light Glasses Prevent Retinal Damage
Cell culture experiments and animal studies have determined that blue light can damage the retina of your eye.3, 4, 5, 6 However, there is not enough research evidence to suggest that blue light absorbing devices are beneficial for reducing the risk or progression of retinal conditions such as age-related macular degeneration .1
Alongside this, many regulations have been put in place to limit the amount of blue light emitted by everyday objects. Due to these safety limits, the levels of blue light that are emitted from objects like light bulbs and digital screens are not high enough to cause retinal damage. This means that wearing blue light blocking glasses when using digital screens is not really necessary.
Noticed a change in your eyesight?
1 in 3 people in the UK have reported deteriorating eyesight as a result of increased screen time.9 If youre considering glasses for screen use, youve probably noticed a recent change in your vision too, or are experiencing some new eye symptoms. Our opticians can take a look at your eyes to check for any changes, and advise on the best lens options for you if needed.
Can You Test For Blue
Many online resources that suggest you can test blue-light-blocking glasses at home with DIY tricks, such as looking at some overlapping blue circles on your screen or shining a light through the lenses onto photosensitive paper. We tried these methods, but we couldnt find any difference between the pairs we tested and, short of a $5,000 spectrometer, theres no way to know for sure how any particular pair will perform. The best way to determine whether a pair of glasses will work for your eyes is to try them .
When youre ready for an upgrade, The Vision Council, which represents optical manufacturers like EyeBuyDirect and Zenni, said buying prescription glasses from a professional with medical-grade blue-light-blocking lenses is the safest bet. And if you want to confirm the results for yourself, you can ask them for a spectral report, which details how much light and at which wavelengths their lenses actually block.
Daily Blue Light Exposure Is Exploding
The average persons blue light exposure has increased exponentially in recent years as smartphones and laptops become more prevalent in daily life. But physicians are observing that blue light exposure may actually damage our eyes, according to a 2018 research review .
To help reduce damage from blue light, blue light glasses and lenses have been introduced. These may help limit the amount of blue light exposure your eyes get every day.
Researchers are still working to understand what blue light can do to your eyes over time.
Read on to learn what we know about blue light glasses, as well as what you can do to help prevent negative side effects from this type of light.
Do Blue Light Glasses Actually Work
As digital spaces have become one of the main ways we work, socialize and communicate with each other, its 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 eyesand 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 purportedly combat the negative impact screens can have on our eyes. But are they really worth buying? We asked two experts to weigh in.
What Scientific Research Says About Blue Light Glasses
So far, research doesnt support the idea that blue light glasses can relieve digital eyestrain symptoms, such as headaches, dry eyes, or blurred vision. There havent been any scientific studies that have proven they have any sort of health benefits, says Vivienne Sinh Hau, MD, an ophthalmologist at Kaiser Permanente in Riverside, California.
According to a trial published in February 2021 in the American Journal of Ophthalmology, blue light glasses worn during a two-hour computer task did not change eyestrain symptoms whatsoever. And another small study, published January 2019 in Optometry and Vision Science, found that even though a blue-blocking filter used on a computer screen blocked 99 percent of wavelengths between 400 and 500 nanometers, it didnt alleviate digital eyestrain symptoms any more effectively than a neutral filter.
Thats likely because blue light isnt the only reason for digital eyestrain. The screen-related issues that people are having with their eyes are indeed more likely related to dry eye, eyestrain things like that, says Lauren Branchini, MD, an ophthalmologist at UMass Memorial Medical Center and an assistant professor at UMass Medical School in Worcester, Massachusetts.
In short, because blue light isnt to blame for the headaches and dry eyes youre feeling, blue light glasses likely wont help.
Is Staring At A Screen For Hours Each Day Bad
The short answer? Probably.
Doctors and researchers are largely focused on two issues that arise from our ever-growing screen time: Digital eye strain and blue light exposure.
According to the American Optometric Association, digital eye strain is “a group of eye- and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use.” Those issues range from blurry vision and dry eyes, to headaches and neck pain.
By staring at screens all day, we’re also exposed to blue light waves, which are said to cause a myriad of issues. There is conflicting evidence about how blue light exposure affects your eyes, but doctors and researches are in agreement that it does affect your circadian rhythm. More on that below.
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 is from sunlight. It’s also artificially emitted from our digital devices and LED light bulbs.
As blue light is close to UV light in the spectrum and we know the risks that UV light pose to the skin and the eyes it’s been the focus of many studies, says Dr Nisha Sachdev, ophthalmologist and director at the Australian Society of Ophthalmologists.
“However, I don’t believe there’s any evidence to suggest that normal environmental exposure to blue light, including that emitted from digital screens, causes any measurable damage to our eyesight,” she says.
Optometrist Luke Arundel from Optometry Australia agrees. “The level of blue light exposure from computer screens and mobile devices is less than that absorbed when you step out into natural sunlight and is below the international safety limits,” he says. “So at this stage, we don’t need to worry about computers or phones ‘frying’ our eyes.”
I Found Other Ways To Dial Back On Blue Light
Since the glasses made me more aware of blue light, I tried remedying the issue further with small fixes. My iPhone is now set for “Night Shift” from 9 p.m. to 7 a.m. The Night Shift function alters the colors of the phone’s display to the warmer end of the color spectrum, so you’re exposed to less blue light that way.
To do this yourself on an iPhone, you can go to Settings > Display & Brightness > Night Shift, and set the time you usually start getting ready for bed.
I also zeroed in on non-screen sources of artificial blue lights. I learned that while LEDs are also increasingly popular as room lights, they’re not all the same. Warm white bulbs with less blue tend to work better at night than cool white ones. There are also multiple bulbs that that can change the intensity of a light’s colors with an app, or you can buy reduced-blue LED bulbs for warmer lights in bedrooms.
What Our Testers Say
“According to the Felix Gray website, their sleep blue light lenses are made to filter the range of blue light that impacts melatonin secretion. After wearing the glasses for a little over two weeks, I felt like I slept a little better. I also seemed to get fewer headaches after long work nights writing at my computerso for that alone, they were definitely worth it for me. One thing to keep in mind is that the glasses are on the fragile side. If you live in a home with young children or you plan to commute with the glasses, its definitely something youll want to keep in mind.” Simone Scully, Verywell writer and product tester
Give Your Eyes A Break
If youâre worried about how computers and other blue light-emitting screens are affecting your eyes, you can find relief without special eyewear.
The American Academy of Ophthalmology, the Vision Council, and other vision-related organizations urge moderation in screen use. Most of them recommend adopting the 20-20-20 rule. That means that every 20 minutes, youâll look at an object at least 20 feet away for 20 seconds.
The American Academy of Ophthalmology also recommends taking these steps:
- Adjust your seat, or the position of your computer, so your eyes are about 25 inches from the screen. Position the screen so youâre gazing slightly downward.
- Use a matte screen filter on the screen to reduce glare.
- Use artificial tears when your eyes feel dry.
- Pay attention to the lighting in the room where you work. You might try increasing your screen contrast.
If you wear contact lenses, give your eyes a break by wearing glasses now and then.