Blue Light Filtration
In today’s age, there is a massive of emphasis on living a healthy lifestyle. People want—and often demand—eating healthy. However, this lifestyle extends beyond food. A healthy work life is just as important. Work-life balance is key, but so are the practices you employ at work. Standing desks have become more and more prevalent as more studies indicate the negative impact sitting has on your health. Similarly, more studies are underway to research the negative effects of the overwhelming screen use that is now part of our daily routine. Blue light is a major part of this conversation. Below, we’ll explain what blue light is, where it comes from, where it’s present, and the negative effects it has.
What is Blue Light?
White light is colorless light, like ordinary daylight. It is composed of all elements of the visible light spectrum at equal intensity, like red light, green light, and blue light. Each element of visible light has its own wavelength range, which is measured in nanometers. There is an inverse relationship between the length of the wavelength and the energy that it contains. Accordingly, longer wavelengths have lesser energy while shorter wavelengths have more energy. This is because the frequency is higher for shorter wavelengths.
Blue light exists on the farthest, highest end of the visible light spectrum. It’s energy is so high that it sits right next to UV light—abbreviated for ultraviolet light—on the complete light spectrum. As such, blue light has the shortest wavelengths. In contrast, red light exists on the complete other end of the spectrum. Just as blue light sits next to UV light, red light sits next to Infrared.
The negative effects of ultraviolet light is well documented. Specifically, it can harm cells by directly damaging DNA and causing mutations that can cause cancer. At the very least, too much sunlight can actually burn our skin (see: sunburn). This is why we wear sunscreen! It’s also why it’s good to wear UV protecting sunglasses. Just as this light can harm our skin cells, it can also harm our cornea. Issues like sun-blindness are common among people that are overexposed to UV rays without eye protection (surfers are a perfect example).
Where does Blue Light come from?
Blue light is all around us, though that was not always the case. When Thomas Edison invented the first practical, commercially viable lightbulb in 1878, the light was incandescent. This would stay true for years. The problem is that incandescent and other forms thereafter were energy inefficient.
Enter the LED (light-emitting diode), which is an electric component that emits light when connected to a direct current. LEDs can emit light both on the visible light spectrum and the invisible light spectrum (like Infrared and UV light). In essence, LEDs are semiconductors that have been built to emit light when they’re activated. While LEDs were initially discovered in 1907, it took nearly a century to apply this technology for normal screen use because the blue diode had yet to be created. As mentioned before, white light needs equal intensity from every wavelength in the visible light spectrum. While scientists had created other diodes (like red, green, and yellow), they had not cracked the blue diode because its creation required certain crystals that they weren’t yet able to create in a lab.
However, as technology got better, scientists became better equipped to solve this long standing problem. By the early 1990s, three Japanese engineers (Isamu Akasaki, Hiroshi Amano, Shuji Nakamura) solved created the first blue diodes, which opened the door to white light, practical, every-day use of LEDs. And as time progressed, LEDs became more and more prevalent because of their amazing efficiency (more on that below). LEDs are now integral to our day-to-day and as such blue light exists in everything from computer displays to artificial light (like light bulbs).
The benefits of Blue Light / LEDs
What makes LEDs so amazing is how energy efficient they are. They can last up to 100,000 hours, which is particularly incredible when compared to fluorescent lights (10,000 hours) and incandescent bulbs (1,000 hours). And not only do LEDs last longer, but they use less energy. A modern LED lightbulb converts more than 50% of the electricity it uses into light; contrastingly, incandescent bulbs have a 4% conversion rate! As human beings use more energy in this world, which impacts our environment, the impact of blue diode creation to open the gates to practical, everyday LED use is incredibly important. Imagine if we were still using fluorescent or incandescent bulb to light our digital devices!
Our eyes and Blue Light
Unfortunately, our eyes are particularly poor at blocking or filtering blue light. Through evolution, our eyes never developed a blue light filter. In fact, our eyes are far more effective at blocking UV light. Only ~1% of UV light actually enters into our eyes. And when we’re wearing UV protective sunglasses, it’s even less!
Our ocular blue light filter is even worse when we’re younger. Beginning around age 40, a naturally occurring pigment builds up in our eye that works as a blue light filter. However, before then, we have very little protection. And cataract surgery removes this pigment, which is why blue light filtering protection is so critical to younger people and cataract patients post surgery.
The effects of Blue Light
There are negative effects of blue light given that our eyes act as a poor blue light filter. Even the best inventions have cons associated. And while it’s important we continue to use energy efficient lighting, like LEDs, we need to protect ourselves from short term and potential long term negative effects.
1. Digital Eye Strain
Digital Eye Strain (DES)—also known as Computer Vision Syndrome (CVS)—is a group of symptoms associated with the overuse of digital devices. They include eye fatigue, headaches, dry eyes, blurry vision, dry eyes, neck pain, shoulder pain, back pain, itchy eyes, and general eye discomfort. While DES is not permanent it is nonetheless aggravating (who likes to be uncomfortable?).
Blue light can contribute to Digital Eye Strain for a variety of reasons. Its high frequency light can stress out the eye. Additionally, LEDs are powerful lights bother because of the contrast sensitivity between the light and the surrounding lighting. Glare can also contribute to Digital Eye Strain, which computer screens also produce.
2. Poor Sleep
Blue light suppresses melatonin secretion, which is a chemical that makes us sleepy and helps manage our circadian rhythm. The sun produces both UV light and blue light. When we were caveman, this blue light would enable us to wake up in the morning and be tired by the nighttime, when there was no blue light. However, today’s world has changed quite a bit. Most of us are up into the night and many times in front of our screens (staying late at work, watching TV, reading on our phone or tablet). Because of this, we expose ourselves to blue light way past the time that we’re supposed to receive it. As such, blue light can be one of the reasons that it’s hard for many of us to fall asleep.
A good night’s sleep is incredibly important. More and more studies link poor sleep with poor health. Scientists have shown that it can increase our weight while others have linked poor sleep to certain cancers. While some studies are still yet to be confirmed, it’s clear that sleeping well is important to health, let alone our productivity. How much harder is it to work well after sleeping too few hours?
3. Macular Degeneration
Just as UV light can harm our cornea and skin, more and more studies are linking an overexposure of blue light to macular degeneration. The macula is part of the retina a vital part of our vision; without it, we cannot see. There are eye doctors believe that the overexposure to blue light, due in large part to our dependency on digital devices, can damage our retina. They point to things like the rise in and the earlier timing of age-related macular degeneration.
Being careful about macular degeneration is particularly important to older generations that have had cataract surgery. Starting by the time we’re 40, our eyes start to develop a pigment that naturally filters blue light. However, cataract patients have this removed from their lens and therefore are highly susceptible to blue light.
It’s important to note that this is a new field of study because high energy lit screens are new, as is our overwhelming dependency on computers (at the turn of the millennia all our smart phones could do were call and text). There are studies done in stem cell and animal models that point to blue light harming our retina, and there are others that question those beliefs. Regardless, there is no harm in filtering blue light. Many times, it’s often better to be safe than sorry.
Solutions to Mitigate Blue Light
1. Computer Glasses
Eye care is incredible important. At Felix Gray, we believe that computer glasses are the best way to mitigate blue light. Our lenses are specially designed to effectively filter blue light without compromising a clear lens. Other lenses either use an ineffective coat that looks clear (unless in front of a screen, and then it looks blue because it deflects blue light) or have a yellow tinted lens that is effective, but—you know—looks yellow. These yellow glasses are often referred to as blue blockers. At Felix Gray we developed a proprietary lens that itself filters blue light so that it can be the perfect balance between clear and effective. We do so by taking a naturally occurring pigment (that begins around age 40) and synthesizing it in higher volume. We then combine this pigment with other materials to ensure that the lens is clear.
2. Apps, and do they work?
There is a rise of software and apps that claim to filter blue light by changing the color of the screen to a redish-orangish hue. For instance, Apple released Night Shift. This certainly changes the color temperature of the screen, which has its benefits in eye comfort, but is not changing the actual LED lights producing blue diodes (i.e. what produces blue light). Blue light is a component of any light that has white in it at all, because blue is needed to make the light that color.