If you want to improve the contrast of your TV without having to buy a brand-new set, bias lighting is an easy and relatively inexpensive way to do it. Bias, in this context, means that light is projected at an angle to your TV; more specifically, onto the back of your TV or onto the wall behind it, so that it casts a dim halo around the display.
Once installed, a bias light can boost the apparent contrast of your TV, making blacks and dark areas of the picture look deeper than they did before. Bias lighting can also help ease the strain of looking at a bright TV screen in a darkened room.
Bias lighting for TV sets and computer monitors takes a variety of forms. Most common are peel-and-stick strips of LEDs that adhere to the back of the screen, either in a single strip or on multiple sides of your display. There are also bias lights that sit next to or behind your set, casting a dim (or in some cases, not so dim) light on the wall.