Too Much Screen Time: But Do You Need Blue-Light Glasses?
The pandemic has drastically impacted how we socialize, interact, learn, and work. It’s no surprise that, during the pandemic, our screen time dramatically increased.
Remote working, home-schooling, and interacting through digital devices have all led to most of us spending more time staring at screens. Some people are now questioning what impact all that screen time might have on our eye health.
Through our digital devices, we’re exposed to more blue light than any other humans in history. Concerns over eye health have led to an interest in blue light-filtering glasses. But are they worth the investment?
We’ve looked at the evidence — here’s what you need to know.
What is blue light?
Blue light is one of the visible types of light within the human light spectrum. Blue light is emitted by electronic devices, LED lights, and even the sun.
Blue light has a short wavelength of 450–495 nanometers. This means it has a higher frequency than other types of light.¹
We’re naturally exposed to blue light throughout the day from the sun, which impacts our bodies. Blue light from the sun helps regulate our circadian rhythm, a natural cycle related to sunlight that impacts our sleep–wake cycle, blood pressure, mood, and many other bodily processes. During the day, blue light helps us be alert and active, while a lack of exposure at night signals to our body it’s time to sleep.
These days, we’re not just exposed to blue light during the day, and our post-pandemic world has exaggerated this phenomenon. Now we’re being exposed to more blue light than ever.
The widespread use of digital devices — through computer screens, laptops, flat-screen televisions, cell phones, and tablets — exposes us constantly to light-emitting diode (LED) technology which emits blue light.
93.6% of adults increased screen time during lockdown
It’s no secret that the pandemic has increased our screen time. A systematic review of 89 studies found that the amount of time spent on screens increased significantly for almost all age groups as a result of the COVID-19 pandemic.²
One study found that 76% of the population aged between 16 and 24 are spending more time on their phones. It was also found that 45% of people are spending more time on their laptops, and 22% are spending more time on tablets.³
An incredible 52% increase in screen time was also found in those aged 12 to 18 years during the pandemic.⁴
A US study found that 12- to 13-year-old children doubled their non-school-related screen time in May 2020.⁵
Research also showed screen time for American adults increased by 60%–80% after the onset of the pandemic.⁶
A 2020 study found that during COVID-19 lockdowns, 93.6% of adults reported an increase in screen time since the lockdown began, with the average increase in time being approximately 2.8 to 4.8 hours daily. However, total screen time per day was approximately 3.74 hours to 8.65 hours.⁷
A total of 62.4% of people reported experiencing sleep disturbance. Nearly the entire sample, 95.8%, reported at least one symptom of digital device usage, such as eye-related concerns.
But while concerns are growing, does blue light actually impact eye health? It appears that the evidence may not support what some experts claim.
These increases have been associated with a range of health effects, including challenges with mental health, sleep, and diet.²
Some experts believe that devices could be causing other issues. Exposure to blue light through our screens is one cause for concern for some experts. The exposure could be affecting eye health.
The evidence of blue-light exposure
Some experts have raised concerns about blue-light exposure and eye health, which has led to an increased interest in blue-light glasses. The sales of blue-light glasses are booming, and many eyewear companies are reporting dramatic increases in their blue-light products.⁸
Tamiesha Frempong, MD MPH, an ophthalmologist at Mount Sinai Hospital in New York, said that interest has risen “[e]specially in the pandemic, with kids doing remote learning, lots of parents have come in asking about them.”⁹
Research, however, has not found a link between poor eye health and blue-light exposure. It turns out that blue-light glasses may be more hyped-up than helpful.
Some researchers have claimed there is no evidence of blue light causing any damage to the eyes.¹⁰
Further, according to the American Academy of Ophthalmology (AAO), “there is no scientific evidence that the light coming from computer screens is damaging to the eyes. Because of this, the Academy does not recommend any special eyewear for computer use.”¹¹
They also state, “The amount of light coming from a computer has never been demonstrated to cause any eye disease. A study reprinted by the National Library of Medicine found no measurable UVA or UVB radiation (the most harmful part of light) from computer screens.”¹²
However, it’s important to remember that, although that’s the official recommendation, research in this area is relatively new. The long-term effects of blue light are not yet known, and recommendations could change over time.
Blue-light glasses: hyped-up or helpful?
As we’ve seen, special glasses that filter out blue light have grown in popularity — a trend that’s being driven by the pandemic. Some of those glasses cost US$100 or more. But are they worth the investment?
Blue-light glasses have specific lenses that are said to provide relief from blue light associated with screens while protecting eye health.
It appears, though, that blue-light glasses may offer little to no benefits.
The American Macular Degeneration Foundation (AMDF) claims there’s no evidence that blue light is bad for eye health. While they do state that UV glasses can be useful for sun protection, blue-light glasses do not hold such a benefit.¹³
The organization states, “…the blue light emitted from the sun and the blue light emitted from electronic devices are significantly different. While most of the research agrees that UV-blocking sunglasses are an important protective measure against sunlight exposure, the research on blue light emitted from electronic devices is contradictory and inconclusive.”
They also wrote, “…right now there isn’t much evidence to support wearing blue light blocking lenses for everyday electronics use.”
In alignment with this, a 2021 trial found that blue-light glasses worn during a two-hour computer task did not change eye-strain symptoms at all.¹⁴
Experts recommending blue-light glasses against scientific evidence have incurred serious fines. In the UK, opticians at Boots pharmacy were fined around $40,000 for making claims about blue-light glasses protecting eye health.¹⁵
So it appears that blue light is unlikely to be the cause of any eye health impacts related to screen use. Instead, general eyestrain is likely the cause.
Can devices cause eyestrain?
Devices can indeed cause a degree of eyestrain––particularly if they are used for long periods. Staring at screens for extended periods leads to decreased blinking, which can lead to eyestrain symptoms.
In fact, 90% of people who use digital devices experience digital eyestrain. Symptoms include:¹⁶
Dry eyes
Blurred vision
Headaches
Neck and shoulder pain
It’s important to recognize, though, that eyestrain is caused by the way we use devices, not the devices themselves or the blue light that’s emitted from them. Eyestrain can be improved through a range of techniques.
The AAO states that most symptoms of eyestrain caused by looking at computers or devices are temporary.
“Most eye symptoms caused by computer use are only temporary and will lessen after you stop using the computer. If you continue to experience these symptoms, contact your ophthalmologist.”¹⁷
How to avoid eyestrain
While eyestrain can be uncomfortable, it’s typically temporary, and there are many ways in which you can lessen the effects.
Some factors that can contribute to eyestrain include:
The distance between your eyes and the screen
Screen glare
Poor posture
Insufficient lighting
The AAO has specific recommendations for avoiding the effects of eyestrain, including:
Check the distance between your face and the screen, which should be ideally 25 inches — roughly an arm’s length
Adjust the lighting in your room to ensure there’s not too much screen glare or contrast.
Use a matte screen filter to help reduce glare if necessary.
If you experience dry eyes, use artificial tears to add moisture to the eyes and reduce discomfort.
If you’ve been prescribed glasses or contact lenses for screen use by an optometrist, use them whenever you’re looking at a screen.
The organization also recommends the 20-20-20 rule. This involves three steps:
Every 20 minutes
Look away from your screen at an object 20 feet away
Keep looking for at least 20 seconds. This will ensure that you give your eyes regular breaks.
If you have any concerns about your eye health, it’s essential to check in with a registered optometrist. They will likely give you an eye test and may recommend wearing glasses or contact lenses if necessary.
Blue-light glasses may help sleep
While there’s no significant evidence to support the use of blue-light glasses for eye health, there may still be some benefits to wearing them.
Blue light impacts our circadian rhythm, and using devices, especially in the evening, may impact our sleep quality.
Pre-technology, humans were exposed to blue light during sunlight hours only. In our high-technology world, we’re constantly exposed to blue light through our phones, laptops, and other devices. This can mean that our natural circadian rhythm doesn’t kick in as it should, and you may not feel sleepy when you want to go to bed.
Some small studies have found blue-light glasses helpful for improving sleep. It’s worth noting, however, that this research is new and needs further investigation.¹⁸
When it comes to sleep health, another strategy is to turn off devices an hour or so before bedtime to help your body prepare for sleep.
It doesn’t appear blue-light glasses cause any harm. According to the Baylor College of Medicine, since some people feel blue-light glasses help with sleep, there’s likely no harm in giving them a try.¹⁹
The lowdown
Rising screen time during the pandemic has led to an increased interest in blue-light glasses. However, it appears they may not be worth the hype.
Our devices, including smartphones, laptops, tablets, and computers, all emit a type of light known as blue light. We are also exposed to this from the sun, and it helps to regulate our circadian rhythm.
While some experts have raised concerns about blue-light exposure in relation to eye health, the current evidence doesn’t appear to support claims. Eyestrain appears to result from screen exposure not specifically caused by blue light.
According to the AAO, eyestrain is typically temporary and can be managed through a few strategies, including staying an arm's length from screens, adopting the 20-20-20 rule to give your eyes regular breaks, and avoiding screen glare through proper lighting and screen covers as needed.
The AAO also recommends wearing glasses when using devices if they have been prescribed by an optometrist. If you have any concerns about your eye health, visit a registered optometrist for a check-up. They may prescribe glasses or contact lenses if needed.
While blue-light glasses typically aren’t recommended for eyestrain, they could be beneficial for sleep health, though research in this area is new. Sleep can also be improved by avoiding device exposure an hour or so before bedtime.
While there’s plenty of hype about blue-light glasses, it seems the main benefit they bring is a possible improvement in sleep quality, not relief from eyestrain.
Sources:
Wavelength of blue and red light | UCAR - Center for Science Education
The health cost of screen time | Lenstore
Adolescents’ recreational screen time doubled during pandemic, affecting mental health | University of California San Francisco
Impact of the COVID-19 lockdown on digital device-related ocular health (2020)
Do blue light glasses work? A scientific look at their possible benefits | Everyday Health
What is blue light? A complete scientific guide | Everyday Health
Digital devices and your eyes | American Academy of Ophthalmology
Ultra-violet and blue light aggravate macular degeneration | American Macular Degeneration Foundation
Boots opticians fined £40,000 over misleading blue light advertising | Asocciation of Optometrists
Are blue light-blocking glasses worth it? | American Academy of Ophthalmology
Attenuation of short wavelengths alters sleep and the ipRGC pupil response (2020)
Chloe Garnham is a writer exploring a broad range of topics, including healthcare, education, and technology.
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