The dangers of ultraviolet radiation have long been known, and we have been advised to protect ourselves against it for almost as long. Hats, sunscreen, and UV protecting sunglasses are must haves in the summer time, and increasingly so in the winter. We know that we need to guard against UV radiation to prevent painful sunburns, damaged vision, and cancer.
The irony is that while doing all that, we are bringing high-energy visible light into our own homes, and overdosing on it.
The advent of the blue LED has changed how we live. Smart phones, tablets, flat screen computers and televisions have become ubiquitous in our daily lives, and many people are adopting compact florescent or LED light bulbs. And for good reason too, the screens using LED technology are smaller and lighter than previous technologies. Likewise all of these technologies are more efficient and economical than cathode ray-based screens or incandescent light bulbs. However, these new efficient and economical technologies have a hidden cost that few know about.
That cost is related to the unnaturally high amount of high-energy blue light now in our lives.
What is Blue Light?
Blue and violet light are the most energetic wavelengths of the visible spectrum of light. The well known visible spectrum that makes up the colors of the rainbow – Red, Orange, Yellow, Green, Blue Violet – is really just a small slice of light’s spectrum. As light’s wavelength decreases, the energy of the light increases.
What Are Blue Light’s Health Risks?
While the use of blue and violet light is much more efficient than earlier technologies, it is not without risks.
While not as energetic as ultraviolet light, high-energy visible light is energetic enough to cause cell damage. That plays a role in retina damage and can accelerate age related macular degeneration. However, that isn’t the full extent of blue light’s impact on our lives.
We have known since 1981, when Dr. Charles Czeisler first proved it, that the human body uses light to keep its circadian rhythm regulated to its environment. In the absence of artificial lighting, the human sleep-wake cycle tends to follow the sun.
One of the most important aspects of the circadian rhythm is melatonin production by the brain. Melatonin is a hormone that influences the circadian rhythm by relaxing the body and promoting sleep. While all light waves inhibit melatonin production to some degree, high-energy visible light has the greatest effect. Disrupting melatonin production delays falling sleep and important REM sleep. Sleep deprivation itself has a number of serious consequences, including irritability, loss of mental acuity, and is also associated with obesity and diabetes.
So, while all artificial lights have some effect on the circadian rhythm, the increasing prevalence of blue light, and exposure to it throughout the night, is having a tremendous effect on our bodies.
Children and teenagers are especially at risk. Both because of their increased need for sleep, and their tendency to keep at least one electronic screen on throughout the night.
What Can We Do About Blue Light?
Despite the increasingly widespread use of blue light, there are several ways to combat its ill effects. The first, and most obvious, is to limit your exposure to it. If possible, limit your time using smart phones, tablets, computers, or watching flat screen TVs. The damage caused by high-energy visible light is cumulative, so limiting your exposure is a great way to cut down on your risk. Changing displays to warmer, more red, color palates decreases the amount of blue light your screens emit. Also, since the intensity of light decreases the further you are from the source, sit back from your screens.
With particular regards to blue light’s effect on your circadian rhythm, turn off electronic devices two to three hours before bed time. Instead of watching television or surfing the internet before bed, try reading a book by a light source that uses a softer, “warmer”, more red light. That allows your body to produce melatonin at a normal rate before bed, and increase your quality of sleep.
There are also other options available for those who wear glasses. Several lens manufacturers have incorporated technology to screen high energy blue light similarly to ultraviolet light.
BluTech – BluTech lenses combine a durable lens material with natural eye pigments that oxidize in blue light, automatically blocking it. The use of natural pigments means the BluTech lenses offer the same protection, color enhancement, and contrast as the natural human lens.
Hoya – Lens manufacturer Hoya offers several specialty lenses to fill a variety of customers’ needs:1) Computer Lenses are designed to provide a wide, clear field of view while working at arms length, such as when using a computer. They also block glare from digital screens to reduce eye strain.2) Phoenix Lenses are designed with kids in mind. They block high-energy visible light as well as ultraviolet light, and are extra durable, to cope with outdoor play and all the other rigors of childhood.
3) Sync Lenses are designed for all-day comfort while focusing on smart phones, tablets or e-readers. Sync Lenses help your eyes to relax while focusing on small screens, blocking glare and reducing the fatigue associated with using these devices.
Crizal Prevencia – Prevencia lenses from Crizal use a special coating to prevent harmful ultraviolet and high-energy blue light rays from entering the eye, while allowing the lower energy blue rays that help to combat certain sleep disorders and seasonal depression through. Prevencia lenses also use anti-reflective and anti-glare coatings for additional protection.
Technology is a wonderful thing. It has allowed us to communicate and share ideas or information like never before in human history. Like most things, there are risks to go along with the rewards of digital displays and LED lights. With some forethought, however, these risks can be dealt with. Limiting your exposure is a great way to control the health risks of blue light. If you can’t limit how much time you spend looking at electronic screens, such as if you use a computer for work, be sure to ask about lenses that screen high-energy blue light. You’ll get better sleep and your eyes will thank you.
Alpert, O.D., M. (2014, September 23). How to Protect Your Eyes From the Negative Effects of Digital Devices and Blue Light. Retrieved May 17, 2015, from http://www.huffingtonpost.com/dr-matthew-alpert-od/blue-light_b_5570433.html
Blue light has a dark side – Harvard Health. (2012, May 1). Retrieved May 17, 2015, from http://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side
Karp, A. (2013, September 9). Protecting Eyes From ‘Bad’ Blue Light. Retrieved May 17, 2015, from http://www.visionmonday.com/business/labs/article/protecting-eyes-from-bad-blue-light-vm-090913/
Ultra-violet and Blue Light. (n.d.). Retrieved May 17, 2015, from https://www.macular.org/ultra-violet-and-blue-light