Human Health & Blue Light
When lightbulbs were first invented in 1879, they opened the doors for people to be able to spend more time awake and outside of their homes at night. People were able to work longer hours, spend more time at stores, restaurants, and sporting events, and travel more safely in the dark. The invention of the lightbulb over 140 years ago has helped give us the ability to do anything at night that can be done during the day!
Over time light bulb technology got better and more energy efficient. The old incandescent bulbs that have been used since 1879 that produced a warm glow of light are more recently being replaced by bright LEDs that conserve energy and come in a wide range of colors. If you are reading this on your computer, tablet, or phone, you are looking at handfuls of small LEDs in the screen. If artificial light from lightbulbs give us the ability to do more at night and LEDs can produce brighter light using less energy, surely there isn’t anything wrong with them, right? Not quite. The unfortunate truth is that artificial light, especially from LEDs, puts out blue light that can be harmful to us in many ways.
What is Blue Light?
The visible light spectrum is separated into different colors, like you see when you look at a rainbow. Each color corresponds to a different wavelength, with longer wavelengths appearing redder and shorter wavelengths appearing bluer. These shorter blue wavelengths produce higher amounts of energy and are naturally emitted from the sun. Only 150 years ago the sun was the only source of blue light, which scatters in the atmosphere to make the sky look blue. But now we are surrounded by blue light throughout the day and night thanks to artificial lighting. Even though lightbulbs don't appear fully blue to our eyes, all artificial lighting creates some amount of blue light, with LEDs producing more than other bulbs.
How does blue light affect us?
Humans, like most life on Earth, rely on day and night for our circadian rhythm. When the sun sets and the sky gets dark, our bodies start producing melatonin. This is a natural hormone that is best known for helping us sleep at night, but it also has other benefits including lowering cholesterol, boosting our immune systems, and helps the functioning of the thyroid and reproductive organs. When people are exposed to artificial light at night, whether that is light inside of your home or outside, the body gets tricked into thinking there is still sunlight and inhibits the production of melatonin. This reduction in melatonin and prolonged exposure to blue light has many negative effects on the body, including increased risk of sleep disorders, diabetes, depression, obesity, prostate or breast cancers, memory impairment, eye strain, and more.
What Can You do to Lessen the Affects?
If you are like most people, you probably spend a good amount of time on computers, tablets, smartphones, or watching TV for your job or in free time. Especially now, with many aspects of our lives reliant on these devices, it can be hard to escape from blue light. However it is still possible to reduce your exposure and lower the risks. Below there are some easy things that you can you can implement now and do every day.
· Limit use of screen time before bed by turning off electronics or charging devices in a separate room from your bedroom.
· Use the 20-20-20 rule: For every 20 minutes of screen time you should look at an object at least 20 feet away for at least 20 seconds.
· Download applications to smartphones, tablets, or computers that lessen the output of blue light, like F.lux, Lux for Android, or Twilight
· Purchase a pair of blue light blocking glasses and wear them whenever you use your devices.
· Buy warm toned lightbulbs, for indoors and outdoors, that have color temperatures of less than 3000K on their packaging. These lightbulbs produce smaller amounts of blue light.
Sources:
https://blutechlenses.com/blog/what-is-blue-light/
https://www.thoughtco.com/the-visible-light-spectrum-2699036
https://www.darksky.org/light-pollution/human-health/
https://arxiv.org/pdf/2007.02063.pdf
https://time.com/5033099/light-pollution-health/
https://www.rasc.ca/sites/default/files/LightPollution-EffectsonHealth.pdf
https://www.hsph.harvard.edu/news/press-releases/outdoor-light-night-breast-cancer/
By Amanda Leith
