What are Blue light filter glasses?
Blue-light blocking glasses have filters in their lenses that block or absorb blue light and in some cases UV light, from getting through. That means if you use these glasses when looking at a screen, especially after dark, they can help reduce exposure to blue light waves that can keep you awake.
So do blue-light blocking glasses really make a difference for all of us who stare at a screen 8-plus hours per day? The answer isn't as straightforward as yes or no.
Is staring at a screen for hours each day bad?
The short answer? Probably.
Doctors and researchers are largely focused on two issues that arise from our ever-growing screen time: Digital eye strain and blue light exposure.
According to the American Optometric Association, digital eye strain is "a group of the eye- and vision-related problems that result from prolonged computer, tablet, e-reader, and cell phone use." Those issues range from blurry vision and dry eyes to headaches and neck pain.
By staring at screens all day, we're also exposed to blue light waves, which are said to cause a myriad of issues. There is conflicting evidence about how blue light exposure affects your eyes, but doctors and researches are in agreement that it does affect your circadian rhythm. More on that below.
What is blue light?
All visible light we humans see contains the entire spectrum of the rainbow, from red to violet. Within that spectrum are blue light waves, which are said to help us stay alert and upbeat.
Any source of visible light gives off blue light waves, whether it's the sun, a touchscreen, or a light bulb.
We get plenty of blue light waves each day from the sun, but after dark, we're still exposed to it from many artificial sources.
How does blue light affect sleep?
When the sun goes down, the lack of light signals our bodies to start producing melatonin, the hormone responsible for making us fall asleep.
Before the advent of artificial light, the sun regulated our sleep schedules. But today, we're exposed to light all day and into the night. While exposure to any light waves after dark delays our bodies' production of melatonin, blue light waves can be especially problematic because they keep us alert.
On the other hand, blue light can help us overcome sleep issues by disrupting our usual circadian rhythm. The Lumos mask, for example, uses light therapy to mitigate the effects of jet lag.