As we spend more and more time at home and staring at screens, we're becoming increasingly vulnerable to eye strain. You've probably already heard of blue light and how it can hurt your eyes, and maybe a pair of blue light blocking glasses caught your attention. But it's important to understand that there are lots of options for reducing eye strain when staring at screens, and they go beyond just getting new lenses. Here's what you should know about blue light, and some of your choices for reducing your exposure to it.

What Is Blue Light?
On the most basic level, blue light is exactly what it sounds like: light that's blue. That's not the full picture, though, and this is where light and color theory come into play, along with concepts like color temperature, Planck's Constant, and the black body radiation curve. Without going too far into the weeds, you simply need to understand one fact about light: The color white isn't universal.

There is no singular white, but a whole range of visible light that counts as white. Depending on the lighting conditions and what is radiating and reflecting light, white light can appear very yellow (warm) or blue (cool) in color. For instance, the light coming from an incandescent LED light bulb is warmer than the light coming from a computer monitor. This is called color temperature, and it's measured in kelvin (K).

What we perceive as white light shifts along a range of generally 2,700K to 7,000K. Confusingly, warmer light has a lower color temperature than cooler light, with the almost fiery glow of tungsten hitting around 2,800K and overcast sunlight hitting about 6,000K.

Computer monitors typically set white at a very cool temperature to emulate natural sunlight, close to 6,500K. That means the light coming from your screen is quite blue, which you'll notice if you look from a web page with a white background to a warm light bulb. Blue light has been accused of causing eye strain and even eye damage, so naturally the solution should be to warm that light up before it hits your eyes.

https://www.pcmag.com/how-to/give-your-eyes-a-break-how-to-choose-the-right-blue-light-glasses