The Unhealthy Effects of Blue Light (and 7 Solutions)
Blue light emitted by the digital screens you use everyday may be affecting your health. In this article, discover how your body interacts with high-energy visible light and what steps you can take to reduce your exposure.
- The science behind blue light
- Effects of blue light on your sleep
- Effects of blue light on your eyes
- Other potential health effects of blue light
- Effects of blue light on your productivity
- How to reduce blue light exposure (a checklist):
The science behind blue light
Today, it is normal for us to spend our time looking at brightly-lit LED screens from morning to night. It didn’t used to be.
Digital screens are sources of artificial blue light or high-energy visible light. Understanding the physics of light and how your eyes interact with high energy visible light will help you understand why too much blue light from screens can be bad for you.
When we say ‘light’, what we really mean visible electromagnetic radiation waves. All the different colors we see in our daily lives sit within the visible light spectrum, which is a section of the electromagnetic radiation spectrum.
Different wavelengths within the visible light spectrum represent different colors. The longest wavelength of light that humans can see is red. The shortest is violet. Ultraviolet (UV) light has an even shorter wavelength, but we can’t see it.
Longer wavelengths are easier on our eyes because they are lower energy. Blue light sits in the upper end of the visible light spectrum. It has a shorter wavelength which means it has more energy. As a result, when we are exposed to blue light, it penetrates all the way through to the retina, located in the back of your eye.
Anything above 380 nanometers is not visible to the human eye and cannot be seen. But even though high-energy UV light is not visible to the human eye, its short high-energy wavelengths can be harmful to us. Too much can cause skin cancer or eye damage. It’s why we protect ourselves from UV light with sunscreen and sunglasses.
We actually need high-energy visible light to help us regulate our sleep / wake cycle, also known as our circadian rhythm. During the daytime blue light lets your body know that it needs to be awake by reducing melatonin levels, the hormone responsible for helping us sleep.
The health effects of blue light
Effects of blue light on sleep
Many experts agree that blue light emitting devices have an impact on our sleep patterns. Generally speaking, the amount of artificial high-energy visible light we are exposed by phones, laptops and other digital devices has increased: we use LED screens for longer, at closer proximity and more frequently than ever before.
As manufacturers try to find more efficient ways to provide high-quality visuals, the light from our devices is now often “short-wavelength-enriched”. This means it has a higher concentration of blue light than natural light. While screens are getting bigger and brighter all the time, research suggests that it’s not great for your sleep pattern.
Graph from a 2015 study showing increase in blue light in modern devices compared to older devices (Source: Frontiers)
Artificial light sources such as LEDs, fluorescent bulbs and incandescent bulbs can disrupt your natural sleep cycle. The circadian rhythm is determined by the amount of light and dark that your body is exposed to - and blue light affects levels of the sleep-inducing hormone melatonin more than any other wavelength. Since high-energy visible light tells your body it needs to be awake, it can mean you can actually get less sleep:
- Inhibits melatonin production: Blue light tells your body when we need to be awake - at sunrise for example. However, when you are exposed to artificial blue light it can affect your physiology in unnatural ways. Studies show that looking at screens can interfere with the production of melatonin, the chemical responsible for helping you sleep.
- Disrupts circadian rhythm: Daylight keeps a person's internal clock (aka circadian rhythm) aligned with the environment. However, in today’s world you are subjected to more artificial sources of blue light than ever before. This can disrupt your natural circadian rhythm and make it more difficult to fall asleep at a regular time each night.
- Using digital devices at night doesn’t help: While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The study found that blue light suppresses melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).
How blue light affects your eyes
Eye strain (and computer vision syndrome)
Since blue light waves have a shorter wavelength, they flicker more than shorter wavelengths. This feedback creates glare and reduces contrast, which makes your eye muscles work harder to process what you see. That is the reason why your eyes may feel more relaxed when you read from paper compared when you read from an LED screen. Prolonged exposure to computer glare can make your eyes feel tired and lead to headaches and blurred vision.
In addition, when you use computer, smartphone and television screens you blink less (and sometimes not fully) which can make your eyes dry. On average we only blink 3 to 8 times per minute when reading, watching TV, listening to a podcast, working on a computer, or another activity that requires intense focus. This is up to 60% less than an average blink rate. Blinking is important for lubricating your eyes and removing debris. The fact you blink less when you are using digital devices can actually intensify eye strain and associated symptoms.
Long-term eye damage?
Welding goggles provide eye protection during some forms of welding and cutting. They are intended to protect the eyes not only from the sparks and debris created by welding, but also the optical radiation and the intense ultraviolet light produced by an electric arc (the bright light created by the prolonged electrical discharge - see above).
Own a pair of sunglasses? We know that too much exposure to UV light from the sun increases the risk of serious eye diseases such as cataracts and cancer. And, in the same way that UV light can harm our cornea and skin, there are more and more studies are linking an overexposure of blue light to macular degeneration - a condition that can lead to blindness.
The macula is part of the retina. It's a crucial part of our vision and without it, we cannot see. There are eye doctors that believe the overexposure to blue light, due to our dependency on digital devices, can damage our retina. Some of them reference the growing number of macular degeneration cases, as well as the fact that people now develop it at younger ages.
It makes sense that there is less research on blue light exposure from screens: devices that emit high-energy visible light simply haven’t been around that long.
While research is still in its early stages, mounting evidence suggests that taking preventative action against exposure to blue light may be sensible.
For context, people once thought smoking tobacco was good for their health (and doctors even endorsed it). Much like vaping and other new phenomena, scientific research into long-term effects needs time to catch up before there is any empirical evidence.
Other potential blue light health concerns
Today, our use of digital devices means we are exposed to more blue light than ever before. As more and more research is conducted, the effects of blue light on the body have also been linked to a number of more serious health conditions, such as:
- Heart disease
- Reduced libido
Why blue light may impact your productivity
The effects of blue light can knock your system out of balance. The consequences can spill over into other parts of your life too: namely, your productivity.
Exposure to blue light can make it difficult for you to maintain a regular, healthy sleep pattern - something which can impact your ability to perform at your highest level.
Nowadays, hustle culture is the new norm. And even though research shows that long hours damage both productivity and creativity, millennials are still working 12-18-hour days - at the expense of their well-being.
But unless you have a genetic mutation, most of us need 7-9 hours of sleep in order to operate at optimum capacity.
Furthermore, eye strain and Computer Vision Syndrome can make it more challenging to focus during tasks which involve using digital devices. Not only does this make you less productive in the short-term, but it can lead to a vicious cycle of missed deadlines and increased pressure, which unchecked, may contribute to burnout.
Checklist: 7 ways to reduce the effects of blue light
1. The 20-20-20 Rule
An easy way to protect your eyes against eye strain from blue light in devices is to take regular breaks using the 20-20-20 rule. Every 20 minutes, move your eyes to look at an object at least 20 feet away, for at least 20 seconds.
Use Google Chrome? Download our 20-20-20 timer which reminds you to take regular breaks from the screen.
2. No devices before bed
Using devices before bed exposes you to blue light and may make it more difficult for you to fall asleep and/or get a full, restorative night’s sleep.
Try to keep at least 1 hour before bed technology-free. Not only will this help you reduce your exposure to HEV light, but if you replace it with a more focused activity such as reading a book, then you'll also gain the added benefit of being more relaxed.
If you must use a device before bed, you might want to try blue light blocking glasses. (see #4 for more information).
3. Conscious device use
Let’s face it, modern work increasingly revolves around digital devices. That means it can be difficult to limit your screen time in professional situations.
And, even if you don’t use screens at work, it’s not always easy to resist checking your Instagram feed or sending a WhatsApp message to your friends.
That's why using devices consciously in your spare time is a great way to reduce your blue light exposure - and it's totally within your control.
Why not try limiting digital device use to a specific period during the day or setting a specific amount of time during which you can use devices. Or if you frequently talk to your friends via technology, how about meeting them in-person more often (if that's possible).
4. Blue light blocking glasses
Blue light blocking glasses can help you reduce your exposure to high-energy visible light. LUMES computer glasses:
Filter blue light: Too much blue light can lead to eye strain, headaches and sleep cycle disruption. It may also contribute to long-term eye damage. LUMES glasses filter blue light from digital devices. Even though they’re virtually clear, our lenses filter out the highest energy wavelengths of 420-440 nm. This can help to protect against the immediate, and potential long-term effects of blue light exposure.
Eliminate glare: Your eyes have to constantly focus and relax to read pixels on screens which puts more stress on your eye muscles. All LUMES lenses have a premium Anti-Glare coating, preventing unnecessary feedback from entering your eyes. It helps to reduce digital eye strain, visual fatigue and blurry vision.
Better sleep: Blue light tells our body when we need to be awake. That's why looking at screens during the evening can interfere with the production of melatonin, the chemical responsible for helping you sleep. Studies show that blue light blocking lenses can help you maintain a normal circadian rhythm, and help you get better quality sleep.
5. Use an app
You can use an app like f.lux at night to slowly decrease your computer’s blue glow as the sun sets. Apps which change the color temperature of your display can be helpful in reducing your exposure to blue light. However, you should also consider that viewing your display in a yellowish hue can be disruptive in some situations. If you’re doing any work or activity that involves seeing the colors on the screen for what they actually are (graphic design, for example), then fitting f.lux around your routine may be challenging.
Another way you can reduce the intensity of blue light from digital devices is by using night mode. If you are an iPhone user you can use Night Shift (under Settings > Display) and the less-known Color Tint feature. If you have an Android device you can download Twilight to lower the amount of HEV light it emits. If you're using a desktop, you should be able to find similar apps specific to your device.
6. Consider diet
Good nutrition helps to support the healthy functioning of your eyes. Recent research suggests that two nutrients are key to guarding against cataracts and macular degeneration: lutein (pronounced: LOO-tein) and zeaxanthin (pronounced: (zee-ah-ZAN-thin).
In nature, lutein and zeaxanthin appear to absorb excess light energy to prevent damage to plants from too much sunlight, especially from high-energy light rays.
In addition to being found in many green leafy plants and colorful fruits and vegetables, lutein and zeaxanthin are found in high concentrations in the macula of the human eye, giving the macula its yellowish color. In fact, the macula is also called the macula lutea (from the Latin macula, meaning spot and lutea meaning yellow).
7. Visit an optician / get an eye test
If you're experiencing discomfort with your eyes, or have any issues with your vision it's always a good idea to visit a professional optician who is trained to recognize abnormalities.
Opticians can prescribe glasses or contact lenses, or refer you to further treatment with other medical professionals if it’s required.
Our eyes don’t always hurt when there is something wrong with them which is why it’s a good idea to arrange regular eye tests.