Most of us view some type of electronic device for many hours each day. This includes TVs, smartphones, tablets, and gaming systems. But how does the blue light from those screens affect our health?
Melissa Barnett, principal optometrist at the UC Davis Eye Center, explains blue light and its impact on your eyes and health.
What is blue light?
Blue light is part of the visible light spectrum – what the human eye can see. Vibrating within the 380 to 500 nanometer range, it has the shortest wavelength and highest energy.
About one-third of all visible light is considered blue light. Sunlight is the biggest source of blue light. Artificial sources of blue light include fluorescent light, LED TVs, computer monitors, smartphones, and tablet screens.
Are there health benefits of blue light?
Blue light boosts alertness, helps memory and brain function, and elevates mood. It regulates your body's natural wake and sleep cycle (circadian rhythm). Sunlight is also important for the growth and development of eyes and vision in children.
How harmful is blue light?
Blue light exposure from screens is small compared to the amount of exposure from the sun. However, there is concern about long-term effects of screen exposure from digital devices. This is especially true when it comes to too much screen time and screens too close to the eyes.
According to the Vision Council, 80% of American adults use digital devices more than two hours per day. Nearly 67% use two or more devices at the same time. Fifty-nine percent have symptoms of digital eye strain.
Since our eyes are not good at blocking blue light, nearly all visible blue light passes through the front of the eye (cornea and lens) and reaches the retina, the cells that convert light for the brain to process into images.
Constant exposure to blue light over time could damage retinal cells and cause vision problems such as age-related macular degeneration. It can also contribute to cataracts, eye cancer and growths on the clear covering over the white part of the eye. According to a vision study by the National Eye Institute, children are more at risk than adults because their eyes absorb more blue light from digital devices.
People also tend to blink less when using digital devices, which contributes to dry eye and eye strain. Other common signs of eye strain include headaches, blurred vision, and neck and shoulder pain. According to the Vision Council, 27% to 35% of Americans reported experiencing one of these symptoms after using digital devices.
How does blue light affect sleep?
Exposure to blue light before bedtime also can disrupt sleep patterns as it affects when our bodies create melatonin. Interruption of the circadian system plays a role in the development of type 2 diabetes, cardiovascular disease, cancer, sleep disorders, and cognitive dysfunctions.
Will blue light glasses help with eye strain?
While there are many studies on blue light glasses, there isn’t consensus. However, they can help protect eyes from eye strain caused by overexposure to blue light. If you spend a lot of time using digital devices and notice digital eye strain, blue light glasses may be helpful.
Are blue light glasses worth it?
Wearing blue light glasses during the day can help people fall asleep, stay asleep, and have a more restful sleep. Generic lenses that filter blue light reduce negative effects by 10% to 23% without reducing quality. Computer glasses with yellow-tinted lenses may increase comfort when viewing digital devices for long periods of time.
How can I reduce negative effects of blue light?
- Get blue-light filters for your smartphone, tablet, and computer screen. The filters prevent much of blue light from reaching your eyes without affecting the visibility of the display.
- Follow the 20-20-20 rule to reduce digital eye strain. Take a 20-second break to view something 20 feet away every 20 minutes.
- Control lighting and glare on your device screen. Set up a good working distance and posture for screen viewing. Confirm that even minor vision problems are properly corrected.
- Talk with your eye doctor about blue light protection and digital device use at your next eye examination.
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FAQs
Blue Light Can Keep You From Falling Asleep
How does blue light affect your eyes, sleep, and health? ›
How does blue light affect sleep? Exposure to blue light before bedtime also can disrupt sleep patterns as it affects when our bodies create melatonin. Interruption of the circadian system plays a role in the development of type 2 diabetes, cardiovascular disease, cancer, sleep disorders, and cognitive dysfunctions.
How does blue light affect sleep experiment? ›
More so than any other color, blue light messes with your body's ability to prepare for sleep because it blocks a hormone called melatonin that makes you sleepy. Bottom line: You're less drowsy than usual at night, and it takes you longer to fall asleep.
Why is blue light good for your eyes? ›
According to a recent NEI-funded study, children's eyes absorb more blue light than adults from digital device screens. Blue light is needed for good health: It boosts alertness, helps memory and cognitive function and elevates mood.
How does light affect your sleep? ›
Sleeping with lights on can disrupt your circadian rhythm and hinder sleep quality. Artificial light, especially blue light, can suppress melatonin production. Excessive light exposure can impact your sleep-wake cycle and negatively affect your overall health.
Is blue a good light for sleep? ›
Despite being a calm-inducing color on most occasions, blue is not suitable for lighting a bedroom. In fact it's quite the opposite: blue lights throw the sleep cycle off and decreases the production of melatonin. That's why smartphones, tablets and desktop screens, all rich in blue light, should be avoided at night.
How does bluelight affect your mental health? ›
These high levels of blue light cause an increase in our stress hormones cortisol and adrenaline which leave us feeling highly stressed, irritable, and anxious. The best way to combat this issue during the day is to use specifically designed blue light computer glasses that filter blue light by 50%.
Is light sleep good or bad? ›
Despite its name, light sleep is no lightweight when it comes to your health. It's a key stage of sleep that delivers benefits to your brain and body, including codifying memories and boosting creativity. And that's nothing to sleep on, given that about half of your time asleep — about 50% — is spent in this stage.
Is blue light bad for your skin? ›
Blue Light and Your Skin
Research shows blue light from electronic devices can lead to changes in your skin cells, including cell shrinkage and death. These speed up the aging process. Even exposures as short as 60 minutes can trigger these changes.
How does light affect blue eyes? ›
Generally speaking, patients with lighter color irises, such as blue or gray, experience more light sensitivity than someone with brown eyes. The density of pigment in light eyes is less than that of a darker colored iris. When light hits a dark-colored iris, the higher density in pigment blocks the light rays.
If you were born with blue eyes, there are a few benefits you might not be aware of: Because less melanin allows for more light to pass through the eye, those with blue eyes can often tolerate longer periods of lower light. Blue eyes appear to have a lower risk of developing cataracts than brown eyes.
What are the side effects of blue light therapy? ›
PDT, however, may induce early and late onset side effects. Erythema, pain, burns, edema, itching, desquamation, and pustular formation, often in association with each other, are frequently observed in course of exposure to the light source and in the hours/days immediately after the therapy.
How harmful is blue light? ›
Blue light from electronics is linked to problems like blurry vision, eyestrain, dry eye, macular degeneration, and cataracts. Some people have sleep issues.
What does blue light do to your brain? ›
Exposure to blue light in the evening or at night has been shown to increase alertness and improve performance on reaction time tasks, most likely as a result of the suppression of the evening onset of melatonin, which leads to a phase delay of the circadian rhythm.
How bad is blue light for sleep? ›
Light therapy, and blue light in particular. View Source , can help realign the body's circadian rhythms and improve sleep. Inversely, exposure to blue light in the hours leading up to bedtime can hinder sleep. Blue light suppresses the body's release of melatonin.
How does blue light interfere with a child's sleep? ›
In children, blue‐enriched LED lighting has a greater impact on melatonin suppression and it inhibits the increase in sleepiness during night. Light with a low color temperature is recommended at night, particularly for children's sleep and circadian rhythm.
How does blue light affect night vision? ›
The bluer and brighter the light, the stronger the effect. The pupils immediately restrict to block out the offensive light and it will take another 30 minutes to readjust to seeing in a dark environment.
How does blue light affect the circadian rhythm? ›
Exposing the eyes to blue light (or white light, which includes blue light) during the sensitive periods triggers photoreceptors in the retina to send a signal to suppress melatonin and shift circadian rhythms. These photoreceptors do not respond to red light and minimally respond to yellow and orange light.
