In recent years, the term “blue light” has been popping up everywhere. With screen exposure on the rise due to more and more time spent on electronic devices (computers during the day and phones in our downtime), Americans have increased their blue light exposure. But what is blue light and is it causing us harm?


Blue light is one of several colors in the visible light spectrum and has a short wavelength between 400 and 500 nanometers. The main source of blue light is from the sun. Blue light from normal sun exposure during the day can actually help with alertness, mood, attention span and memory. However, blue light is also found in fluorescent and LED light sources. These are common in electronics, such as computer screens, cell phones and TVs, and can be detrimental, especially at night1.


Just how does blue light affect our bodies?


Eye strain

In response to a study conducted at the University of Toledo in 2018, Dr. Ajith Karunarathne said, “It’s no secret that blue light harms our vision by damaging the eye’s retina.” While the negative effects of blue light on they eye has been a concern among the scientific community, there is still some dispute about whether the amounts from electronic devices to which we’re exposed is high enough to cause damage. Dr. Karunarathne, assistant professor in the University of Toledo’s Department of Chemistry and Biochemistry, is also concerned with the uptick of age-related macular degeneration cases in the U.S. saying, “By learning more about the mechanisms of blindness in search of a method to intercept toxic reactions caused by the combination of retinal and blue light, we hope to find a way to protect the vision of children growing up in a high-tech world.” 2


Sleep Cycles

Exposure to light at night, especially blue light, can disrupt our bodies natural 24-hour cycles known as circadian rhythms. One of the most important circadian rhythms for humans is the sleep-wake cycle3. Exposure to light suppresses the release of melatonin in the body, a hormone that affects our circadian rhythms. Blue light at night has an even more powerful effect. It suppresses melatonin for about twice the amount of time as green light. In short, exposure to light at night, especially blue light, can really mess with how much sleep you are getting and in turn cause a myriad of negative health effects.



How can you protect against it?


1.Reduce your blue light exposure

This is the most obvious and easiest action to take — avoid looking at bright screens at least two to three hours before bed (and yes, this includes your phone). You can also make a switch to using dim red light for night lights which is less likely to affect your melatonin levels. Another tip is to make sure to take in bright light from the sun during the day which can help with sleep.


2. Blue light-blocking glasses

If avoiding blue light is not possible, there are products that can help reduce its impact on your body. Blue light-blocking glasses filter out only blue light and are helpful for those who are often around electronic screens. They are especially important for those of us who use their devices at night or work night shifts. Check out these blue light-blocking glasses that come in many styles for both kids and adults.


3. Adapt your screen

To reduce your exposure from blue light, you can also adjust the settings of your electronic devices. There are apps like f.lux that reduce blue light exposure from your laptop by filtering out blue and green light at night. You could also buy screen protectors for your electronic device that adhere to the monitor and reduce blue light.


Regardless of the solution you choose, be sure to consider all the ways to limit your exposure to blue light and start to apply these changes to workdays and evenings.



1. Blue light has a dark side - Harvard Health

2. UT chemists discover how blue light speeds blindness | UToledo News

3. What is Circadian Rhythm? | Sleep Foundation