Bias lighting can help reduce the eye strain caused by long exposures to TV screens and monitors in dark rooms, but it can also help make the greys and blacks on your screen seem richer.
Bias lighting is placed behind a TV to increase the ambient light around the screen without shining more light in the viewer's eyes. This type of light helps reduce eye strain and fatigue by keeping our eyes from constantly trying to adjust to the bright light levels of the screen in contrast to the dark light levels of the room. Over at the How-To Geek, former Lifehacker writer Jason Fitzpatrick explains how some basic bias lighting cranks up the contrast on your screen using the optical illusion above as an example:
...our eyes perceive grey to be darker and richer when seen against a lighter background and more washed out when seen against a light background. Illuminate the wall behind your screen and the same contrast illusion takes effect: the greys and blacks on your screen will appear richer and the contrast will seem stronger between them and the surrounding area... many people adjust the values for brightness and contrast to higher levels in order to get the intensity of colour and black contrast they desire. If the environment you're watching the screen in already helps boost the contrast and creates a better looking image on the screen then you can turn the brightness back down.
Fitzpatrick notes that keeping the brightness down on your screen will help extend the life of your TV as well. We've talked about a couple awesome ways you can do it: with a Raspberry Pi, some custom LED strips, and even Arduino-based methods for monitors. Of course, there are also plenty of kits available in stores.
Screens are becoming a bigger part of our life as time goes on, so you might as well do what you can to save your eyes. The whole article at How-To Geek is worth a read, so learn more about bias lighting at the link below.
What Bias Lighting Is and Why You Should Be Using It [How-To Geek]