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.
View our services and specialists at the UC Davis Eye Center
FAQs
Previous research shows that too much exposure to blue light from technology devices can potentially damage the eye's retina, lead to digital eyestrain , and negatively affect sleep quality and duration .
How damaging is blue light to your eyes? ›
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.
What are the symptoms of too much blue light? ›
Common Symptoms of Blue Light Sensitivity
- Eye Strain and Discomfort. Common indications of blue light sensitivity include eye strain and discomfort after spending extended periods in front of screens.
- Headaches and Migraines. ...
- Insomnia and Sleep Disturbances. ...
- Blurred Vision and Sensitivity to Glare.
Protect yourself from blue light at night
Avoid looking at bright screens beginning two to three hours before bed. If you work a night shift or use a lot of electronic devices at night, consider wearing blue-blocking glasses or installing an app that filters the blue/green wavelength at night.
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.
Does removing blue light help you sleep? ›
The bottom line. Blue light, which is emitted from smartphones, computers, and bright lights, may inhibit your sleep if you're exposed to it at night. If you have a history of sleeping problems, try reducing your exposure to blue light during the evenings. Amber-tinted glasses may be particularly effective.
Do TV screens emit blue light? ›
Sources of High-Energy Blue Light
The largest source of blue light is sunlight, but is also emitted by laptops and computer monitors, smartphones, tablets, TV, fluorescent and CFL bulbs.
Do blue light glasses actually work? ›
Eye Health and Vision Fatigue
Studies had from five to 156 participants and ran from less than a day to five weeks. The analysis of the trials showed that there is no short-term advantage to using blue-light-filtering spectacles for reducing vision fatigue, compared with standard clear lenses.
Do screens actually damage your eyes? ›
While using devices will not damage your eyes permanently, staring at them for a long time can cause temporary discomfort. People experience eye strain in different ways, but symptoms can include: dry eyes.
Can you reverse the effects of blue light? ›
If research proves that blue light damages the retina and macula, the eye conditions that develop as a result are generally irreversible. Treatments can only delay vision impairments or improve vision to only some extent and stop these eye conditions from worsening.
Ways to Manage Blue Light
- Blue light-blocking glasses. They're widely sold online. Amber or brown-tinted lenses may help best.
- Cut back on screen time starting 2-3 hours before bed.
- Dim the brightness on your devices. This is often called night mode or dark mode. It changes the background from white to black.
What causes brain fog? Lack of sleep, poor sleep hygiene or blue light exposure before bed can all contribute to brain fog. Looking at blue light before bedtime, such as scrolling on your cellphone, decreases the hormone melatonin, which is essential for deep REM sleep.
What is the best light for sleep? ›
Research studies discovered red to be the best color light to help you sleep, because it increases production of melatonin as well as full darkness. On the other end of the spectrum, blue is the worst. Despite being a calm-inducing color on most occasions, blue is not suitable for lighting a bedroom.
Why does blue light make me sleepy? ›
Blue light suppresses the body's release of melatonin. View Source , a hormone that makes us feel drowsy. While this promotes wakefulness during the day, it becomes unhelpful at night when we are trying to sleep.
What hormone keeps you awake at night? ›
Cortisol. Cortisol is sometimes known as the stress hormone. It's released when you experience stress or anxiety. High levels of this hormone in your blood can prevent you from falling or staying asleep.
Is it OK to sleep with a blue night light? ›
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.
What light color is best for sleep? ›
The best night light colors for sleep are red and amber, as they are warm and soothing colors that promote a good night's sleep. It's thought that colors close to red on the light spectrum stimulate melatonin production.
Is blue light good for night vision? ›
With the shortest wavelength and closest similarity to white light, blue light is the least effective at preserving your night vision.
Is light blue a good color for sleep? ›
The best color for bedroom sleep typically includes shades that are calming and soothing. Blue has serene and tranquil qualities, closely followed by soft greens and earthy tones like beige. These colors tend to lower stress and create a peaceful environment, making it easier to fall and stay asleep.
