Most of what we know about how blue light affects your health is relatively new. Scientists have recently found a relationship between artificial blue light and sleep deprivation, eye strain, headaches and even late-life vision loss.
The latest research has linked blue light to optical damage associated with Age Related Macular Degeneration. AMD is an incurable disease, and is the leading cause of blindness among people over 65. It’s also responsible for about half of severe vision loss in Caucasian Americans over 40.
Of course, blue light has always been around (look up on a sunny day). However, exposure to it has skyrocketed since we became so attached (addicted) to handheld devices and late night TV.
Blue Light and Your Eyes
Light is made up of a spectrum of energy wavelengths. Different wavelengths are either invisible or perceived as the colors of the rainbow.
The most harmful wavelengths to your eyes are the highest energy ones. The highest energy light on the spectrum is invisible, ultraviolet. Thankfully, our eyes have evolved to naturally protect us against the majority of UV rays.
Blue light is the next strongest wavelength, and poses the most risk for damaging the retina. That’s why it’s so important to understand how blue light affects your health.
How Blue Light Affects Your Health – The Good & Bad
Overexposure to blue light has both short and long term effects on your health. The long term effects may not be noticeable until much later in life. However, the damage caused can be pretty devastating.
The short term effects are what many of us experience on a daily basis. Dry, red, watery and itchy eyes; headaches and trouble falling asleep are all short term symptoms. Together, they make up what doctors call Digital Eye Strain. DES is the result of a combination of extended computer use, exposure to blue light, and focusing on a nearby object for too long.
However, blocking blue light out completely isn’t recommended. Blue light has important health benefits, too. It triggers essential physiological responses like pupil constriction and circadian rhythm synchronization – not to mention all the natural beauty you’d miss out on if you couldn’t see it.
AMD and Long Term Effects of Blue Light
Without getting too in the weeds, the long term effects of blue light stem from a series of chemical reactions that happen when blue light reaches your retina. The result can lead to permanent cellular damage and loss of vision. This condition is called Age Related Macular Disease (AMD), and symptoms are difficult to detect.
The primary source of blue light in your daily life is the sun. Solar radiation is 25% to 30% blue light. The sun has always contributed to light-induced retinal damage, but its damage is prolonged over the course of a lifetime.
So what happens when you extend your exposure to blue light well into the night with late night Netflix binging and Instagramming? At this stage, it’s still too early to tell exactly how much more damage might be done with our increased use of LED screens.
Age, genetics, diet, smoking, and exposure to ultraviolet and blue light are the primary contributing factors to an increased risk of AMD. There are multiple stages of AMD, and it’s possible to only have AMD in one eye. Symptoms are difficult to detect in early stages, and there is no cure once diagnosed.
If you spend a significant amount of time on your computer, phone or TV, consider discussing preventative options with your eye doctor.
Digital Eye Strain and Short Term Effects of Blue Light
The Vision Council refers to Digital Eye Strain as physical discomfort after screen use for longer than two hours at a time. More than 83% of Americans reporting that they use a digital device for more than two hours per day. To no surprise, over 60% say they experience symptoms of digital eye strain.
DES symptoms include sore eyes, dry eyes, headaches, blurred vision, increased sensitivity to light, difficulty concentrating, and sometimes neck and shoulder pain. Mayo Clinic says that eye strain symptoms typically aren’t serious and go away after resting your eyes for a bit. Still, Digital Eye Strain can be distracting, taking a toll on productivity and focus at work.
Another short term effect of blue light is disruption of your circadian rhythm.
Light is the most powerful cue for shifting and resetting the time of our circadian clock.
When the retina receives blue light wavelengths, it signals the brain to suppress melatonin, a hormone that regulates sleep and wakefulness. (That’s why it is common to wake up when the sun rises.) When your body suppresses melatonin at night, however, it makes it much more difficult to fall asleep.
What Can You Do?
Scientists are still researching how blue light affects your health. Doctors agree that the 20/20/20 rule is useful for reducing eye strain. Every 20 minutes, look at something 20 feet away for 20 seconds. Try it out the next time you feel strain and take note of how you feel.
Another great tool are blue light glasses. A good pair will reflect a significant percentage of blue light away from your eyes without distorting your vision much. Also, buy a pair with anti-reflective coating. The reduced glare will help with eye strain as well.
Anti-blue light lens technology is advancing. The best lenses allow you to maintain normal vision and color perception while blocking the specific wavelengths of blue light that do the most damage.
Some studies that have shown some vitamins and antioxidants have been successful in lowering the risk of developing advanced AMD. Speak with your eye doctor for more information.
Ultimately, the most important thing you can do to protect yourself from damage from blue light is to limit your exposure. Use the 20/20/20 rule, wear blue light glasses if working for long periods of time, and set time aside before bed without screens.