Blue light is something we encounter every day. We can’t see it, but our eyes and bodies are impacted by it. Let’s shine a light on the pros and cons, and what we can do to protect ourselves from the negative effects of too much “blue light” exposure.
What is Blue Light?
Light comes in different rays—red, orange, yellow, green, and blue. These light rays are differentiated by their energy and wavelength.
Blue light rays have the shortest wavelength and highest energy levels of all visible light rays, and are also known as blue-violet or violet lights. They rank right next to the invisible ultraviolet (or UV) lights. Generally, “blue light” is defined as visible light within the 380-500 nanometers range.
Blue light can be found almost everywhere. Sunlight contains blue light, as it contains the entire light spectrum. High-energy blue light is what makes the sky look blue. Man-made sources of blue light include fluorescent and LED lighting. Computers, tablets, smartphones, and other similar devices emit a specific type of blue light called high-energy visible light (HEV light).
How Does Blue Light Affect Our Bodies?
Blue light can interfere with your circadian rhythm, or internal sleep-wake clock, by suppressing the sleep-promoting hormone melatonin. Thus, high exposure to blue light at night may lead to poor sleep quality and insomnia. On the flip side, blue light can be beneficial in daylight hours; it helps boost attention, cognitive functions, and mood.
Our eyes are not able to effectively filter or block out blue light, though they do block out most UV rays from the sun. Significant blue light exposure can lead to damages in our retinas through macular degeneration, which may lead to permanent vision loss. Some studies may show that digital screens do not emit enough blue light to significantly impact eye health. However, exposing our eyes to any amounts of blue light for long periods of time does lead to general wear and tear in our eyes.
Also, blue light increases the chances of digital eye strain. Blue light is not as focused as other lights and creates visual noise that adversely affects your vision as you look at digital screens. Eyestrain may cause dry eyes and headaches.
Having said all that, not all blue light is bad. A type of depression treatment called “light therapy” uses certain rays of blue light to improve the moods of those who suffer from seasonal depression, or even mental fog. And as we’ve noted, blue light is present in sunlight, which is vital to our health and vitality.
What Can You Do About Blue Light?
While more research must be done to pinpoint exactly how much blue light is too much for our eyes and bodies, optometrists are concerned about the high levels of blue lights emitted by the devices and screens we use every day.
Blue light blocking lens can help reduce the amount of blue light that enter our eyes and reach our retinas. A study in 2019 shows that blue-blocking lenses (BBLs) reduce blue light by up to 43%, thus providing some protection from retinal damage. Blue light blocking glasses or lens can be purchased online.
There are also desktop and mobile apps that reduce the amount of blue light emitted by digital screens. Here is a list of some of the best blue light filter apps on the market today.
Also, make sure that you take breaks and rest your eyes from time to time.
In closing, blue light can both help and harm us. It really depends on how much, and when, we are exposed to it!
-Odelia C
Photo by Randall Meng on Unsplash
Very thoughtful, informative eye-opening article. Disease formation requires co-agent(s) and over time the points you outlined plus the impact of the prolonged 3G-5G overlay likely awakens science.