Blue Light is a type of short wavelength UV light that can be found in just about everything from sunshine to computer screens. A healthy amount of Blue Light from sunlight is good for the human body. However, concentrated amounts of Blue Light from backlit screens like computers, tablets, cellphones, and televisions can be dangerous to your eyes. This coating is also called B+W or Crizal Prevencia As the widespread use of smartphones, tablet devices and computers increases the time we face a screen, more and more people suffer from eyestrain symptoms. One cause of this is believed to be the blue light emitted from the display on such devices. The shorter the wavelength, the stronger energy a light wave has, and this may cause eye fatigue. Blue light, which is next to ultraviolet light on the electromagnetic spectrum, has a shorter wavelength than other visible light. It also tends to be diffused and is believed to cause flickering in the vision. If you have seen the Yellow Gunnar glasses, this is what they claim they are filtering. Though my experience is that they are too yellow, and don't actually do a good job at filtering in the Blue spectrum. There is a movement to generically call all the conditions that make you sensitive to certain light spectrums as irlen syndrome which I think is stupid. Lastly, this is my first 4k Video, and I don't have an animated intro, rendered in 4k yet, so you get the ugly logo for 3 seconds.