HomeConditionsDigital Eye Strain | En Español
By Gary Heiting, OD
What is blue light?
Visible light is more complex than you might think.
Stepping outdoors into sunlight; flipping on a wall switch in your house; turning on your computer, phone or other digital device — all of these things result in your eyes being exposed to a variety of visible (and sometimes invisible) light rays.
Most people know sunlight contains visible light rays and also invisible ultraviolet rays that can tan or burn your skin. But what many don’t know is that sunlight contains a wide range of different-colored visible light rays that contain different amounts of energy.
Sunlight contains red, orange, yellow, green and blue light rays and many shades of each of these colors. The color of individual light rays depends on their energy and wavelength. Combined, the full spectrum of colored visible light rays creates what we call “white light” or sunlight.
Digital electronic devices emit blue light that can cause eye strain and may lead to eye problems over time.
Without getting into complicated physics, there's an inverse relationship between the wavelength of a light ray and the amount of energy it contains. Light rays that have short wavelengths have more energy and those with longer wavelengths contain less energy.
Rays on the blue end of the visible light spectrum have short wavelengths and high energy. Those on the red end of the spectrum have long wavelengths and less energy.
Invisible ray just beyond the red end of the visible light spectrum are called infrared radiation. The “warming lamps” you see in restaurants emit infrared radiation. (But these lamps also emit visible red light so people know the lamps are on! The same is true for other types of heat lamps.)
On the other end of the visible light spectrum, blue light rays with the shortest wavelengths (and highest energy) are sometimes called blue-violet or violet light. This is why the invisible rays just beyond the visible light spectrum are called ultraviolet (UV) radiation.
SEE RELATED: Does red light therapy protect the eyes?
The perils and benefits of UV
UV rays have higher energy than visible light rays (including blue light), which makes them capable of producing changes in the skin that create a suntan. The bulbs in tanning booths emit a controlled amount of UV radiation specifically for this reason.
But too much exposure to UV rays causes a painful sunburn — and even worse, can lead to skin cancer. These rays can also cause sunburned eyes — a condition called photokeratitis or snow blindness.
In moderation, however, UV rays have beneficial effects — such as helping the body manufacture adequate amounts of vitamin D.
Visible light and blue light
Generally, scientists say the visible light spectrum comprises electromagnetic radiation with wavelengths ranging from 380 nanometers (nm) on the blue end of the spectrum to about 700 nm on the red end. (By the way, a nanometer is one billionth of a meter — that's 0.000000001 meter!)
Blue light generally is defined as visible light ranging from 380 to 500 nm. Blue light sometimes is further broken down into blue-violet light (roughly 380 to 450 nm) and blue-turquoise light (roughly 450 to 500 nm).
So, about one-third of all visible light is considered high-energy visible (HEV) or “blue” light.
Key points about blue light
Like ultraviolet radiation, high-energy visible blue light has both benefits and risks. Here are important things you should know about blue light:
1. Blue light is everywhere.
Sunlight is the main source of blue light, and being outdoors during daylight is where we get most of our exposure to it. But there are many other sources of blue light — including LED lighting and flat-panel screens.
Most notably, the screens of computers, tablets, smartphones and other digital devices produce significant levels of blue light.
The amount of HEV blue light these devices emit is only a fraction of that in sunlight. But the amount of time people spend using these devices and the proximity of these screens to the user’s face have many eye doctors and other health care professionals concerned. It's possible there may be long-term effects of blue light from computers and phones on the health of our eyes.
2. HEV blue light rays make the sky look blue.
High-energy blue light rays scatter more easily than other visible light rays when they strike air and water molecules in the atmosphere. This greater degree of scattering of blue light is what makes a cloudless sky look blue.
3. Our eyes are not very good at blocking blue light.
Structures in the front half of the eye (the cornea and lens) are very effective at blocking UV rays from reaching the light-sensitive retina at the back of the eyeball. In fact, less than 1% of UV radiation from the sun reaches the retina, even if you aren’t wearing sunglasses.
(Keep in mind, though, that sunglasses that block 100% of UV are essential to protect these and other parts of the eye from damage that could lead to cataracts, snow blindness, pinguecula, pterygium, and even certain types of cancer.)
On the other hand, virtually all visible blue light passes through the cornea and lens and reaches the retina.
4. Blue light might increase the risk of macular degeneration.
The fact that blue light reaches the retina of the eye is important. Laboratory studies have shown that too much exposure to blue light can damage light-sensitive cells like those found in the human retina.
These changes seen in experimental conditions resemble those caused by macular degeneration, which can lead to permanent vision loss.
Although more research is needed to determine how much natural and artificial blue light from sunlight and digital devices is “too much blue light” for the retina, many eye care providers are concerned. The added blue light exposure in modern life from computer screens, smartphones and other digital devices might increase a person’s risk of macular degeneration later in life. Until long-term population studies can be done, it's too soon to tell.
5. Blue light contributes to digital eye strain.
Because blue light scatters more easily than other visible light, it's not as easily focused. When we spend hours staring at computer screens and other digital devices, this poorly-focused visual “noise” from blue light reduces contrast and can contribute to digital eye strain.
Research has shown that lenses that block high-energy blue light in the 400-450 nm wavelength range increase contrast significantly. Therefore, computer glasses that filter blue-violet light in this range may reduce eye strain — especially if you use digital devices for extended periods of time.
6. Blue light protection is important after cataract surgery.
The lens of an adult eye blocks nearly 100% of the sun’s UV rays. As part of the normal aging process, the eye’s natural lens eventually blocks some short-wavelength blue light as well — the type of blue light with the highest potential to damage the retina and possibly cause macular degeneration and vision loss.
If you have cataracts and are about to have cataract surgery, ask your surgeon what type of intraocular lens (IOL) will be used in your procedure. Some IOLs may be better than others at restoring some level of blue light protection for your retina after surgery.
Also, when outdoors in daylight, always wear sunglasses that block blue light (as well as 100% of the sun's UV rays) after cataract surgery. And when using computers and other digital devices for extended periods, wear computer glasses that provide better blue light protection than standard reading glasses.
7. Not all blue light is bad.
So, is all blue light bad for you? Why not block all blue light, all the time?
Actually, some blue light exposure is essential for good health. So 100% protection from all blue light is not a good idea. Research also has shown that high-energy visible light boosts alertness, helps memory and cognitive function, and elevates mood.
In fact, the application of controlled levels of blue light is sometimes used to treat a condition called seasonal affective disorder (SAD). This is a type of depression that’s related to changes in seasons, with symptoms usually beginning in the fall and continuing through winter.
The light sources for this therapy emit bright white light that contains a significant amount of HEV blue light rays.
Also, blue light is very important in regulating circadian rhythm — our natural wakefulness and sleep cycle. Exposure to blue light during daytime hours helps maintain a healthful circadian rhythm.
But too much blue light late at night (such as reading an e-book or browsing the web at bedtime) can disrupt circadian thythm, potentially causing sleepless nights, daytime fatigue, and even serious health problems.
Blue light filters and protective eyewear
If you are constantly using your phone for texting, emailing and web browsing, a convenient way to reduce your blue light exposure is to apply a blue light filter to the screen of your device.
Digital electronic devices emit blue light that can cause eye strain and may lead to eye problems over time.
These filters are available for smartphones, tablets, and computer screens and are available wherever electronics are sold.
Blue light filters reduce the amount of HEV blue light emitted from these devices from reaching your eyes without affecting the visibility of the display. Some are made with thin tempered glass that also protects your device's screen from scratches.
As mentioned above, blue light-blocking computer glasses can also be helpful to reduce blue light exposure from digital devices. These special-purpose glasses are available without an eyeglass prescription if you don't need corrective lenses or if you routinely wear contact lenses to correct your eyesight.
If you have even mild nearsightedness, farsightedness or astigmatism, prescription computer glasses can optimize your vision specifically for the distance from which you view your devices. This is especially important if you also have age-related presbyopia.
If you're over age 40 and routinely wear progressive lenses or bifocals, prescription computer glasses with single vision (one-power) lenses optimized for your computer viewing distance give you the additional benefit of a much larger field of view for seeing your entire screen clearly. Keep in mind, though, that this type of computer eyewear is exclusively for seeing objects within arm’s length and should not be worn for driving or other distance vision needs.
Also, some anti-reflective coatings for eyeglasses and computer glasses (such as Essilor's Crizal Prevencia AR Coating) provide an added degree of blue light protection from sunlight and digital devices.
You may also want to consider photochromic lenses, which provide UV and blue light protection indoors and automatically darken in sunlight to increase comfort and reduce glare outdoors.
See your eye doctor or optician for more advice on the best computer glasses for viewing your screens and protecting your eyes from blue light.
Age-related maculopathy and the impact of blue light hazard. Acta Ophthalmologica. February 2006.
Phototoxic action spectrum on a retinal pigment epithelium model of age-related macular degeneration exposed to sunlight normalized conditions. PLoS One. August 2013.
Electromagnetic radiation. National Cancer Institute (National Institutes of Health). Accessed May 2021.
Page published on Wednesday, February 27, 2019
Medically reviewed on Thursday, May 6, 2021
FAQs
Is blue light good for you or bad for you? ›
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 is good blue light and bad blue light? ›Blue light is made up of two parts - the 'Good' blue-turquoise, which wavelength ranges from 450 - 500 nm, and the 'Bad' blue-violet, which ranges from 380 - 440 nm. Blue-turquoise light can be beneficial to our health.
How much blue light is bad? ›The short answer to this common question is no. The amount of blue light from electronic devices, including smartphones, tablets, LCD TVs, and laptop computers, is not harmful to the retina or any other part of the eye.
Is it proven that blue light bad for your eyes? ›When you stare at a screen for hours at a time, whether it is a computer, TV, phone or tablet, you are exposed to blue light from the device. Alarmist headlines claim blue light from too much screen time is blinding us. But there is no scientific evidence that blue light from digital devices causes damage to your eye.
What is blue light and why is it bad? ›The blue light from electronic devices messes with your circadian rhythm, or sleep cycle. It signals your brain to wake up when it should be winding down. In one study, as little as 2 hours of exposure to blue light at night slowed or stopped release of the sleep hormone melatonin.
Why is blue light bad for your brain? ›Light from electronic screens comes in all colors, but the blues are the worst. Blue light fools the brain into thinking it's daytime. When that happens, the body stops releasing a sleep hormone called melatonin. Melatonin is nature's way of helping us wind down and prepare for bed.
Is Blue Light good for your skin? ›It was demonstrated that blue light induces an anti-inflammatory and antiproliferative effect; thus, it may be beneficial for hyperproliferative and chronic inflammatory skin diseases such as atopic dermatitis, eczema, and psoriasis. It was also found that blue light might cause the reduction of itching.
Is blue light filter in phone good for eyes? ›The Blue light filter decreases the amount of blue light displayed on the screen of the device. Blue light can suppress the production of melatonin (sleep-inducing hormone), so filtering it out can help you sleep better. It will also reduce digital eye strain, so your eyes won't feel so tired by the end of the day.
Is Blue Light good for sleep? ›Blue light suppresses the body's release of melatonin. View Source , a hormone that makes us feel drowsy. While this may be helpful during the day, it becomes unhelpful at night when we're trying to sleep.
What light is best 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 is blue light good bad? ›
Exposure to blue light during daytime hours helps maintain a healthful circadian rhythm. Too much exposure to blue light late at night (through smart phones, tablets, and computers) can disturb the wake and sleep cycle, leading to problems sleeping and daytime tiredness.
Are phones bad for your eyes? ›Phone screens, and other digital devices, generate blue light differently than natural sources. As a result, the blue light scatters more in the eye, creating more visual noise. The overstimulation leads to eye strain.
Which color light is good for eyes? ›Yellow light, has been proven effective in protecting the retinas of patients exposed to excessive blue light, since it offers the best contrast.
Are blue light glasses worth it? ›A recent study suggested that blue light-blocking glasses do not improve symptoms of digital eye strain. 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.
Does blue light cause dark circles? ›Blue light from screens and lack of sleep are all recognised as key causes of dark circles and fine lines. It is clear that one of the side-effects of modern life are under eye bags.
Does blue light affect everyone? ›Children's eyes are more sensitive to blue light, because, says O'Hagan, “as we age our blue light vision decreases. By the time you get to about 20 your blue light vision is rubbish.” Overall, however, most people are not affected by any of these issues.
What does blue light do to your teeth? ›Once the whitening agent is placed on the surface of your teeth, the blue light activates the whitening agent and starts a chemical reaction. This chemical reaction helps to penetrate the tooth's enamel, lift existing stains in a quicker and more efficient manner, and provide more intense bleaching.
Is blue light only bad at night? ›Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night. And the proliferation of electronics with screens, as well as energy-efficient lighting, is increasing our exposure to blue wavelengths, especially after sundown.
What color makes you sleepy? ›Red light. Red light is by far the best calming light color for sleep. Choosing a red light as a nightlight ensures that you don't disrupt your circadian rhythm. So switching to a red light a few hours before going to bed will surely help you fall asleep easier.
Is blue light bad for heart? ›Studies have also linked blue light exposure at night to increased cardiovascular risks, including obesity. As a result, some health experts recommend using a blue-light filter if avoiding the device altogether is not possible.
Can blue light cause anxiety? ›
A: High levels of blue light can increase our cortisol and adrenaline hormones. The increase in these levels can leave us feeling anxious.
Why is blue light good for face? ›BLUE LIGHT THERAPY
Blue light activates chemicals inside these bacteria, which ruptures their outer walls– destroying the cell and their ability to form acne and other imperfections. Rosacea, psoriasis, wrinkles and sun damage are all ideal candidates for Blue Light Therapy treatments.
Blue light therapy is safe for most people, though it isn't recommended for people with photosensitivity disorders (diseases that cause sensitivity to the sun). When they're used to treat acne, blue light treatments have few side effects, though some people might notice redness or dry skin.
What are the benefits of blue light treatment? ›Blue light therapy is most commonly used to treat sun damage and premalignant or malignant skin cancer growths. It can actually be used to prevent skin cancer and remove both precancerous skin lesions and cancerous skin lesions that haven't spread to other areas of the body (or metastasized).
Should I turn on blue light filter all the time? ›Is it bad to wear daytime blue light glasses all the time? As long as you're working with screens or in artificial lighting, daytime blue light glasses will protect your eyes and health. If you're out in the sun or not being exposed to any artificial light, however, there's no need to wear blue light glasses.
Which filter is best for eyes? ›- 5 Best Apps to Change Eye Color in 2023 [iPhone, Android] YouCam Makeup. FaceTune2. Eye Color Studio by Modiface. Adobe Photoshop. FoxyEyes. ...
- 5 Best Eye Color Filters to Try With a Free Eye Color Changing App. Red Eyes Filter. Blue Eyes Filter. Green Eyes Filter. Black Eye Filter. Purple Eye Color Filter.
Night Light / Blue Light Filter on Android Device
You should be able to find the filter under Settings > Display. Look for an option for Night Light or Blue Light filter and turn it on. In most cases there should be a way to schedule the feature and adjust the color temperature to your liking.
Does TV emit blue light? In short, yes. LED screens that are popular these days emit a great deal of blue light, which can be potentially harmful to the eyes. Therefore, watching too much TV, especially late at night, can suppress melatonin production that makes us ready for sleep.
Can blue light cause headaches? ›Working and playing for long periods on blue light-emitting devices like phones, laptops, and tablets can lead to headaches—but it may not be the light itself that causes problems. It may be posture, muscle tension, light sensitivity, or eye strain.
What color keeps you awake? ›Blue light has the strongest impact. Exposure to blue light (and white light, which contains blue light) during the sensitive period can make it difficult for you to fall asleep and stay asleep. Exposure to white light during the day can have positive effects, including boosting alertness and mood.
What color bedroom helps you sleep? ›
Blue. Blue is perhaps the best color for your bedroom. Not only is it more muted, but blue tones also tend to have more calming effects on the brain, as shown in a 2018 study of blue walls in a university residence hall.
What color light helps with anxiety? ›Blue light therapy is the most effective for anxiety and other mood disorders. This treatment aims to correct both physiological and psychological imbalances. When the body is stressed, blue light can effectively calm it.
Does watching phone at night damage eyes? ›Scientists have uncovered that blue light emission from your smart phone and laptop screens may seem harmless but may be toxic to the eyes and causing macular degeneration, a leading cause of vision loss in the US.
Does watching TV damage eyes? ›Although TVs don't cause permanent eye damage, they can cause eye strain, a common condition that can lead to eye pain, blurry vision, and headaches. Eye strain often occurs after too much screen time, but is more frequent when you're sitting close to the TV or watching from an odd angle.
What color is best for vision? ›In fact, the human eye sees green better than any color in the spectrum. This, along with many other facts about this earthly color, makes it an essential part of our everyday lives.
What eye color is best at night? ›While blue eyes are more sensitive to light during the day, people with blue eyes tend to see better at night – unless there are bright lights. In that case, the lack of melanin makes them as sensitive to light at night as they are during the day.
What color is best for night vision? ›Using a low intensity red light or green light helps preserve your night vision. It shortens the recovery time once you turn off white light illumination and leaves the eye's night vision ready once the low intensity light is turned off.
Are blue light glasses fake? ›Manufacturers claim that blue light glasses can filter out blue light and help reduce symptoms such as headaches, eyestrain, and poor sleep. However, research does not support these claims. People have started to worry about the health effects of blue light emitting from screens.
Why is my vision better with blue light glasses? ›The excessive blue light that we receive from screens, devices, and LED lighting has been scientifically proven to cause eye-strain, disrupt sleep cycle and cause cardiovascular problems. Blue light blocking glasses block or filter the blue light from screens, reduce glare and reduce potential damage to your retina.
Are blue light glasses good for driving? ›Blue light glasses are a great investment if you're looking for a solution to help you see better at night. While they're not the only option for night driving, they are effective in increasing contrast and reducing glare.
Does blue light cause eye wrinkles? ›
Blue light is also known to penetrate the skin deeper, damaging essential proteins and resulting in wrinkles and loss of firmness. “Blue light contributes to premature aging, pigmentation, eye damage, cataracts, cell shrinkage, wrinkles and photo damage,” adds Dr.
Does blue light cause Eyebags? ›Research shows that blue light exposure can lead to oxidative damage in the skin. "This oxidative stress accelerates collagen breakdown and can cause fine lines, wrinkles and bags," explains Dr. Patel. "The damage is further accelerated by squinting (moving the muscles around the eyes a lot which creates fine lines).
Does blue light cause eye dryness? ›Over-exposure of blue light often leads to sleep disruption (remember blue light signals wake time in our natural body rhythms). It also contributes to eye strain and possibly dry eyes. Too much exposure to blue light might be associated with an increased risk of macular degeneration.
Is blue light more harmful than UV to skin? ›Research on the subject is limited, but experts agree that the lower energy and longer wavelength in blue light can penetrate deeper into the skin than ultraviolet (UV) radiation, which can cause skin cancer.
Is UV or blue light more harmful? ›Rays on the blue end of the spectrum have shorter wavelengths and more energy. Blue light is the closest to invisible, ultraviolet light on the color spectrum. Ultraviolet light has the shortest wavelength and is known to be dangerous.
What color light is best 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.
Do blue light glasses really work? ›Manufacturers claim that blue light glasses can filter out blue light and help reduce symptoms such as headaches, eyestrain, and poor sleep. However, research does not support these claims. People have started to worry about the health effects of blue light emitting from screens.
Does blue light cause aging? ›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.
Is A blue light bad for your teeth? ›With teeth made from calcium, the risk isn't to these rigid structures. Blue lights have a massive impact on accelerating the curing of resin-based composites, but they're not strong enough to penetrate the teeth or cause permanent damage to soft tissues.
How can you protect yourself from blue light? ›- Cut down on screen time. Taking regular breaks from computer or TV screens rests your eyes and limits blue light exposure. ...
- Take a break from blue light at night. Screen breaks are most important in the evening. ...
- Get new glasses. Computer glasses with special lenses can lower exposure.
What are the benefits of blue light? ›
Blue light is needed for good health: It boosts alertness, helps memory and cognitive function and elevates mood. It regulates circadian rhythm – the body's natural wake and sleep cycle. Exposure to blue light during daytime hours helps maintain a healthful circadian rhythm.
Which light is good for eyes? ›Warm light is best for the eyes. This includes filtered natural light and light produced by incandescent and LED light bulbs.
Is blue UV light good for skin? ›Blue light therapy is most commonly used to treat sun damage and premalignant or malignant skin cancer growths. It can actually be used to prevent skin cancer and remove both precancerous skin lesions and cancerous skin lesions that haven't spread to other areas of the body (or metastasized).
What color makes you tired? ›Red is the answer to the question of what color of light helps you sleep. Red light causes your brain to produce the sleep hormone melatonin, a hormone released into the body from the pineal gland that helps you mentally and physically relax while you drift off to sleep.
What color helps you wake up? ›Blue light has the strongest impact. Exposure to blue light (and white light, which contains blue light) during the sensitive period can make it difficult for you to fall asleep and stay asleep. Exposure to white light during the day can have positive effects, including boosting alertness and mood.
What happens if you wear blue light glasses everyday? ›Don't worry, you can and should wear Blue Light glasses all day long. It does not have any negative effects. It is safe to use it for as long as you want. In fact, you need to safeguard your eyes from sunlight and artificial sources of Blue Light at all times.
Can blue light glasses cause headaches? ›Some people have reported headaches from blue-light blocking glasses, but there haven't been any reliable studies to support or explain these reports. It is not uncommon to have headaches when you first wear new glasses or your prescription has changed.