Since March of 2020 most of us Minnesotans have found ourselves indoors and looking at screens. Doing schoolwork or working remotely, streaming movies and programs, and those just looking to interact with others via social media or zoom meetings- all of us have had an increase in exposure to blue light. With so many uncertainties surrounding what normal life will look like after COVID 19, one thing that probably will remain is the increase in screen time and blue light exposure for all of us.
What is blue light? Well, to explain we have to go back to ROYGBIV. Sunlight contains all colors of the rainbow creating white light. Each color has a certain wavelength that contains a certain amount of energy. Rays on the red end of the spectrum have longer wavelengths and contain less energy. Rays on the blue end of the spectrum have shorter wavelengths and more energy. Rays that are beyond our ability to see them are called ultraviolet, or UV radiation.
UV rays have higher energy than visible light rays. UV light has beneficial effects, such as helping the body manufacture vitamin D. Too much UV can cause a sunburn or even skin cancer.
Blue light is the visible light range between 380 to 500 nm. One third of all visible light is blue light. Like UV rays, blue light has both benefits and dangers. A few important facts about blue light:
· Blue light is everywhere, indoors and out. Sunlight is the main source of blue light. It also comes from fluorescent and LED lights and flat screen TV’s, computers, ipads, smartphones- all digital devices emit significant amounts of blue light.
· The amount of blue light emitted by digital devices is much less than what comes from the sun. But, because of the amount of time we spend looking at them and how closely we hold them to our eyes the light they emit is more problematic.
· The eye is not very good at blocking blue light. The cornea and lens are good at blocking UV light, and block about 99 % of it (but UV light does damage these tissues over time, causing cataracts and other issues-sunglasses are always a good idea). However, virtually 99% of blue light passes through these tissues without being filtered at all.
· Blue light is essential for good health. Blue light boosts alertness, helps memory, and elevates mood. You do NOT want to block all blue light.
· Blue light is responsible for regulating circadian rhythm- the body’s natural wakefulness and sleep cycle. If you have too much blue light at night it makes it very difficult to fall asleep.
· Blue light causes eye fatigue and digital eye strain. Blue light has a short wavelength- this makes it scatter more easily and is difficult to focus. It makes your eyes feel tired and can even make you get a headache.
· Blue light may be associated with macular degeneration and cataract. Although there is not an actual study to show cause and effect of blue light on eye tissues, logically the inability of the eye to properly filter blue light would cause damage.
What can you do to get enough blue light to help with mood and maintain circadian rhythms, without causing eye fatigue, headaches, and insomnia?
The answer lies in blue light blocking technology in glasses. Even if you don’t need a prescription, using lenses to block the excess blue light from screens significantly decreases eye fatigue and sleeplessness.
It is best to wear these lenses for computer/screen activities only, so you don’t block too much blue light and have the side effects of lethargy and depressed mood.
Switching your devices to night mode on your computer and devices helps also.
So, is blue light good or bad for you? Both. Keeping the level of blue light under control is best, and I believe having a special pair of glasses for screen activities is necessary in our post COVID 19 world.
We have several blue light blocking options available, call to find out more.