We all know the feeling of rubbing our eyes after staring into the void that is a computer screen for an extended period of time. After having just finished your third hour working on that paper or poring over that infuriating Matlab code that refuses to work, your eyes are strained and tired. But what causes this? Do computer screens actually emit signals that hurt our eyes? Is this idea founded? What happens next will shock your eyes.

Blue Light

The eye is able to see a very small spectrum of visible light in the world, from about 380 nm wavelength light to roughly 700 nm wavelength light. This small sliver of visible light is exactly that: visible. Red, orange, yellow lights make up the longer wavelength lights, and consequently do not contain much energy. On the other side of the spectrum (literally), blue and violet light are much shorter in wavelength, and contain much more energy. This category is called High-Energy Visible Light (HEV) or simply Blue Light because of the amount of energy it contains. It is this kind of light that makes the sky appear blue! HEV light is extremely close to ultraviolet (UV) light on the light spectrum. UV light is known to be harmful due to its high-energy output. Light of this particular wavelength and energy levels are potentially very harmful to the body, including the eye.

Because it is so close to UV light on the light spectrum, blue light is also known to be potentially harmful. The human eye is incapable of effectively filtering out blue light from visible light, leaving it susceptible to blue light’s harmful effects, including macular degeneration of the sclera and cornea, as well as the retina and ocular nerve.

Digital Eye Strain

One characteristic of longer wavelength light is that because it has such low energy, it is easily scattered; this means when it hits your eye, only a fraction is absorbed by the eye because the cornea filters and deflects a certain amount of that light. Blue light on the other hand, is shorter in wavelength and therefore higher in energy, meaning it does not scatter as easily. This also means that your eye absorbs much more of it than other shorter wavelength light.

But what does this have to do with computer screens? In general, computer screens are closer in proximity to your face, meaning there is less distance for blue light to travel, giving it a better chance not to scatter by the time its high-energy wavelength hits you right in the eyes. Computer screens emit a large amount of blue light, reducing contrast and thereby directly affecting your eyes.

Relief is Swift and Righteous

Thankfully, there are easy ways to relieve your poor overworked eyes. Certain glasses and screen covers or filters are made especially to help filter out blue light. IT can even be fixed by surrounding yourself with proper lighting, minimizing possible glare on your monitor, and just by blinking your eyes. Other steps can be taken like adjusting monitor settings and optimizing specifications on your setup to help reduce eye strain.

The computer screen can cause irritation in the eyes from overuse, but taking simple breaks and making sure conditions are good and healthy are surefire ways to ensure your eyes are glued to those screens without any worry of continued strain.