3-D TV is a television display technology that enables a three-dimensional effect, so that viewers perceive that an image has depth as well as height and width, similarly to objects in the real world. The technology behind the 3-D effect is called stereoscopy or stereoscopic imaging. In human eyesight, the perspective difference between objects seen through the left and right eyes (binocular disparity), in conjunction with our accommodation (through focusing) to integrate those two perspectives, completes our ability to perceive three dimensions. Traditional 3-D TV (and movies as well) typically work by presenting two separate images – one for the right eye and one for the left – that are incorporated through the use of specialized glasses. Another technology, known as autostereoscopic imaging (auto 3-D), is screen-based and does not require viewers to wear special glasses. Toshiba announced new 3-D TVs with autostereoscopic screen-based technology in November 2010. Toshiba’s display was based on nine separate perspectives of each 2-D frame. Currently, Toshiba’s 3-D display is only available in 12- and 20-inch sizes. Viewers must sit within a 40 degree range, either two or three feet away from the display (depending on the size) for the 3-D effect. Because of bandwidth constraints, cable and satellite-based systems are not yet capable of broadcasting true 3-D. Although the amount of 3-D programming is constantly increasing, what it consists of is actually a half-resolution 3-D signal -- the only real 3-D content currently available for television is 3-D movies, such as Avatar, on Blu-ray discs. All the common TV display technologies, including LCD, LED, OLED and plasma, are capable of including 3-D as a feature. Vendors of 3-D TVs include LG, Mitsubishi, Panasonic, Samsung, Sharp, Sony and Toshiba