You might think all light is the same…but light is so much more complex than you might think!
Light is far from just sunlight...it’s also reading under a nightlamp, working on your laptop, flipping on a light switch, streaming a movie on your large-screen TV, or having virtual meetings on your phone.
Whether it's natural light from the sun or artificial light from energy-efficient light bulbs or the devices you’re on every day, all of these light sources can have a range of effects on your eyes.
In this post, you'll discover what blue light is, is blue light bad for your eyes, sources of blue light, and blue light protection tips you can implement right away!
Table of Contents
- What is Blue Light?
- Are There Any Benefits of Blue Light?
- Blue Light Sources
- Is Blue Light Eye Damage a Myth?
- Blue Light and Digital Eye Strain
- Blue Light and Increased Risk of Age-Related Macular Degeneration
- Blue Light Protection After Cataract Surgery
- Blue Light Delays the Circadian Rhythm
- How to Protect Your Eyes from Blue Light
- Take Supplements to Boost Macular Pigment
- Get More Natural Light
- Wear Blue Light Blocking Eye Protection
- Reduce Screen Time
- Follow the 20-20-20 Rule
- Avoid Bright Screens Before Bedtime
- Don’t Use Your Phone in the Dark
- Limit Screen Time
- Use Phone Hacks to Block Blue Light
- Key Takeaways
What is Blue Light?
Natural light from the sun is made up of all the colors of the rainbow — red, orange, yellow, green, blue, indigo, and violet. When all of these different colors combine, we get white light or visible light; the light we can actually see.
Each of these different colors of light has its own wavelength and energy depending on the color spectrum they belong to:
red light rays = longer wavelengths + less energy
blue light rays = shorter wavelengths + more energy
Wavelengths are also measured in nanometers (nm), which is one-billionth of a meter, and range from 380 nm on the blue spectrum to around 700 nm on the red spectrum.
Blue light ranges from 380 to 500 nm. It is comprised of:
- Blue-violet light (380 to 450 nm)
- Blue-turquoise light (450 to 500 nm)
Combined, the blue spectrum or “blue” light makes up approximately one-third of all visible light and is also called high-energy visible (HEV) light.
What Makes the Sky Look Blue?
High-energy visible (HEV) light rays, which are short-wavelength rays on the blue end of the spectrum, scatter easily when they hit water molecules and air particles in the atmosphere.
A cloudless sky will look blue, depending on the degree of how much these rays scatter.
Beyond the red-light rays of the visible light spectrum is “infrared” light, synonymous with warming lamps you see in local eateries or infrared saunas. The electromagnetic rays just beyond the blue-light spectrum are called ultraviolet (UV) rays.
UV radiation has an even higher amount of energy, and too much UV radiation can cause a suntan or even sunburns. Excessive UV radiation is also harmful to the eyes and may cause conditions such as photokeratitis (snow blindness), or lead to the early onset of degenerative eye conditions.
Below you can see the wavelength vs. energy comparison on the electromagnetic spectrum:
Similar to UV radiation, visible blue light, may expose the eyes to a higher wavelength and energy from the blue spectrum, and cause potential damage to the eyes.
Now that we know that blue light may cause harm, does it also have some benefits?
Are There Any Benefits of Blue Light?
Blue light does have some benefits which include:
- Boosting mood, memory, alertness and cognitive function
- Light therapy used in the treatment of seasonal affective disorder (SAD), a type of depression related to weather changes from fall to winter, uses a bright white light that contains a high amount of high-energy visible (HEV) blue light rays.
- Regulating the body’s biological clock (wake and sleep cycle). Daytime exposure to blue light is fine, however, too much blue light exposure in the evening and nighttime (due to devices) can disrupt the body’s natural circadian rhythm, and cause health problems.
- Exposure to natural sunlight and some blue light is important for children’s growth and development, including vision health.
So yes, some blue light is necessary, but to fully understand why blue light is so much of a concern today, it’s important to take a look at different blue light sources that are now present in our daily lives, and we are constantly exposed to.
Blue Light Sources
Did you know that the most powerful source of blue light is sunlight?
Along with natural light, there are many other artificial sources of blue light which include:
- Fluorescent lighting
- CFL (compact fluorescent light) bulbs and tubes
- LED light bulbs and tubes
- LED television screens
- Computer monitors
Although blue light exposure from devices may be small compared to the amount the sun emits, there is a lot of concern from the scientific and medical community over the long-term effects of artificial blue light due to:
- The proximity of the screen to the face and eyes
- The number of hours spent daily looking at different screens (computer, phone, tablet)
- Noticeable health effects such as digital eye strain, poor sleep quality, depression, and even vision problems like age-related macular degeneration
Next, let’s take a closer look and understand blue light eye damage, and is it something we need to be concerned about?
Is Blue Light Eye Damage a Myth?
If you think that blue light eye damage is just a myth, it’s important to understand the basics of how the eye absorbs light and why blue light damage can be very real.
Less than 1% of UV radiation from sunlight reaches the retina, however, the eye is simply not very good at blocking blue light.
So, even if you aren’t wearing sunglasses, the eye is very good at blocking damaging UV rays from reaching the light-sensitive, delicate retina that enables us to see.
That said, it is best to wear sunglasses that block 100% of UV rays, critical to protecting the eyes from long-term damage which could lead to cataracts or even cancer.
Although the eye virtually blocks all UV rays, it lets through almost all visible light, including visible blue light, which enters the cornea, passes through the lens, and reaches the retina.
Early research shows that too much exposure to blue light can cause eye strain, adversely affect vision, and lead to the premature aging of the eye, which may potentially cause the onset of degenerative eye conditions.
Blue Light and Digital Eye Strain
There are many factors that can lead to eye strain including poor lighting, glare, eye conditions, and staring at a digital screen for hours on end.
As we discussed above, digital devices emit blue light, which being high-energy and shorter in wavelength is able to scatter more easily than other types of visible light.
This means the light is not easily focused, so when you’re looking at digital devices all day long, such as your laptop, phone, and tablet, you’re exposed to a large amount of this type of unfocused light, which can lead to digital eye strain.
Blue-violet light, which is less than 450 nm, can also significantly increase contrast. That is why many eye professionals recommend wearing tinted computer glasses to balance the contrast and provide comfort when viewing a screen.
Blue Light and Increased Risk of Age-Related Macular Degeneration
Due to the fact that blue light is able to pass all the way through to the retina, the delicate lining at the back of the eye, means that light-sensitive cells in the retina can potentially be damaged.
Research suggests that “blue light can penetrate through lens to the retina and cause retinal photochemical damage.”
Many other studies, such as the ones below, have also shown that blue light exposure has both short-term and long-term effects on the health of the eye, which can cause changes in the eye, resembling those of age-related macular degeneration (AMD), a progressive condition that can lead to vision loss.
Although more research is required to determine how much exposure of blue light is considered to be “too much” to lead to degenerative eye conditions, eye doctors recommend to limit screen time, and wear eye UV protection outdoors, to potentially reduce the risk of AMD later in life.
Blue Light Protection After Cataract Surgery
Studies have shown that choosing the right intraocular lens (IOL), used to replace the cloudy lens in cataract surgery, is important to blue light protection.
Research shows that “implantation of blue-light filtering intraocular lens (IOLs) following cataract surgery may have the potential to protect the retina from oxidative damage secondary to blue light and slow the progression of AMD.”
Therefore, it is important to ask your eye surgeon what type of IOL will be used and how much blue-light protection it provides, before going in for cataract surgery. A lens with a blue light filter is especially important for continuing to use digital devices in the long-run.
Blue Light Delays the Circadian Rhythm
Although some blue light is important to boost mood, improve cognition and stay alert, over-exposure to blue light, especially in the evening and close to bedtime can play havoc with the release of the important sleep hormone, melatonin, causing poor sleep, insomnia, and increased fatigue the next day.
Research shows that “artificial-light exposure has been shown experimentally to produce alerting effects, suppress melatonin, and phase-shift the biological clock.”
An article titled, Research progress about the effect and prevention of blue light on eyes, emphasizes that “if blue light is excessive, especially at night when melatonin production peaks, it can not only damage the retina through the ocular surface, but can also stimulate the brain, inhibit melatonin secretion, and increase corticosteroid production, thereby destroying hormonal secretion and directly affecting sleep quality.”
It also mentions that “blue light-induced sleep disorders cause a reduction in eye closing time”, which leads to increased tear evaporation and dry eye syndrome.
How to Protect Your Eyes from Blue Light
Now, that you know that blue light is bad for your eyes, what can you do to reduce it?
There are actually quite a few blue light protection tips that you can include in your day-to-day routine to limit exposure and improve your overall vision.
So, let’s get started on what you can do to protect your eyes from blue light.
Take Supplements to Boost Macular Pigment
Your vision may be adversely affected if there are changes in the macular pigment, a yellow tissue centrally located right in the middle of the eye, in what is called the macula.
Macular pigment is made up of three key carotenoids which are critical for optimal visual function:
- meso-zeaxanthin (MZ)
- lutein (L)
- zeaxanthin (Z)
These powerful antioxidants “work as a filter protecting the macula from blue light and also as a resident antioxidant and free radical scavenger to reduce oxidative stress-induced damage.”
Research has shown that changes or insufficient macular pigment can cause age-related macular degeneration (AMD) and other degenerative conditions.
There are many studies that suggest that supplementation with both lutein and zeaxanthin can increase macular pigment and enhance “visual performance in diseased and non-diseased eyes, and may reduce risk of AMD development and/or progression.”
Pumpkin seed oil is an incredible supplement, rich in zeaxanthin, and aids in protecting the retina. A 2003 study stated that zeaxanthin "may be far more important in preventing or stabilizing macular degeneration than previously realized."
According to the American Optometric Association (AOA), pumpkin also contains lutein along with vitamin A, vitamin C, vitamin E, and zinc making it an excellent supplement to support the macular pigment.
Spirulina supplements also contain high amounts of zeaxanthin. A 2012 study demonstrated that "spirulina can serve as a rich source of dietary zeaxanthin in humans," and "may reduce the risk of cataracts and age-related macular degeneration."
Therefore, adding supplements to your diet is a great way to get the therapeutic dose of lutein and zeaxanthin you need, that you may not be getting from your food.
Get More Natural Light
Artificial light from energy-efficient light bulbs such as compact fluorescent bulbs can expose you to a lot of blue light. LED lighting also emits significantly more blue light than traditional incandescent light bulbs, which although not particularly energy-efficient, are inexpensive and the best to use for your home.
If working from the home or office, if possible, it is best to choose to work in a space that has natural light coming in, to avoid the use of artificial lighting, which can delay your circadian cycle.
It’s also highly recommended to get out in the sun earlier in the day to help boost your mood and concentration levels throughout the day and help you sleep better at night.
Wear Blue Light Blocking Eye Protection
You can minimize the effects of blue light by wearing blue-light blocking eye protection. We have mentioned several options below, but it is best to talk to your eye doctor to determine which type of blue light blocking eye protection will work best for you.
Computer glasses have tinted lenses, such as yellow-tinted lenses that can block blue light, increase contrast, and help to ease digital eye strain from continuous computer use. Additionally, your doctor can prescribe these glasses specific to your viewing distance, which helps to relax the eyes as you work.
Anti-reflective lenses are excellent for reducing glare and increasing contrast. They can also further help in blocking blue light from both natural sunlight and digital devices. It is best to go for lenses that offer blue-light blocking capabilities and also have an anti-reflective coating to reduce glare.
These lenses automatically transition to dark lenses when you are outdoors, similar to wearing sunglasses. Once you are back indoors, they automatically turn clear again. Photochromatic lenses can:
- Filter up to 2x more harmful blue light than standard clear lenses
- Filter up to 8x more harmful blue light from sunlight outdoors
- Provide both 100% protection from UVA and UVB rays
- They can serve as your regular prescription glasses indoors, and sunglasses outdoors
Intraocular Lens (IOL)
Post-cataract surgery, the cloudy lens in your eye is replaced by what is called an intraocular lens (IOL). This lens can help protect the eye from UV light as well as some blue light. However, some types of IOL lenses have a better blue light filter. Therefore, it is important to talk to your eye doctor to make sure you are getting the right IOL lens to best protect your retina from blue light exposure.
Reduce Screen Time
(Image source: Juststand.org)
One of the best ways to protect from blue light is to limit exposure and take frequent breaks from screen time to give your eyes a rest.
Follow the 20-20-20 Rule
A great way to decrease eye strain, and give your eyes a break, is to follow the 20-20-20 rule. For every 20 minutes of screen time, stare and focus at an object or look into the distance, at least 20 feet away, for 20 seconds. Also, make sure to blink often to keep your eyes lubricated!
Avoid Bright Screens Before Bedtime
To ensure you get a proper night’s rest, it is best to avoid or limit bright screens at least 2-3 hours before you hit the pillow. This will ensure you don’t disrupt the production of melatonin, the body’s sleep hormone, and wake up fresh rather than fatigued.
Don’t Use Your Phone in the Dark
Using your phone in the dark can put excessive strain on your eyes, and one study has shown that blue light from phones and tablets may even speed up blindness. Along with eye strain, you may also suffer from dry eyes and prolonged night-time use may cause irreversible deterioration of vision.
Limit Screen Time
If you work on a computer all day, try to at least limit screen-time once you get home from work. For children, too much screen time can impact your child’s wellbeing and vision health. Experts suggest that:
- Kids aged 0-2 years – no screen time
- Kids aged 2-5 years – maximum 1 hour a day
- Kids aged 5-18 years – maximum of 2 hours a day
Use Phone Hacks to Block Blue Light
Whether you own an iPhone, iPad, or an Android phone, there are a few different settings that you can apply on your device to help protect your eyes from blue light.
We highly recommend you configure these settings especially if you use your phone or tablet during the evening and night hours.
Use a Screen Filter
There are special filters available that you can apply to your laptop, tablet, or phone screen to decrease the amount of blue light that hits the retina in your eyes. These filters are usually inexpensive and can absorb quite a bit of blue light emitted from your digital device.
Use Night Shift Mode
In most of the smartphones available today, there is an option called Night Shift which automatically adjusts the colors of your screen’s display to the warmer end of the visible light spectrum. You can configure your phone’s settings to automatically turn on Night Shift mode a few hours before bedtime.
Turn Your Phone Screen Red
Better than turning on Night Shift, is to completely go to the opposite end of the spectrum, and actually turn your phone screen red. Red light is the least likely to suppress melatonin and disrupt the circadian rhythm. Follow the instructions in the video below to learn how to set this up:
- Blue light makes up one-third of all visible light and is also called high-energy visible (HEV) light
- Similar to UV light, blue light has a higher wavelength and energy which can lead to irreversible eye damage
- Some blue light is necessary to boost mood, memory, and alertness and improve cognitive function
- Blue light comes from sunlight and artificial sources such as CFL and LED lighting, computer screens, tablets and phones
- Blue light can cause digital eye strain, increased risk of macular degeneration, and delays in the circadian rhythm
- Boosting macular pigment by taking nutrient-rich supplements can prevent or reverse the onset of progressive eye conditions such as AMD
- Protect from blue light by wearing blue light blocking glasses, avoiding and reducing screen time, and using night shift mode