As television manufactures prepare to roll out their 3D-ready sets, engineers are slowly but surely taking on the next hurdle: 3D TV without the cumbersome glasses. "Hold onto your remote control: 3-D television is on the way. By the end of the year, most of the major TV manufacturers, including LG Electronics, Panasonic, Samsung and Sony, will be selling displays capable of showing 3-D movies and other programming. Unfortunately, none of the models going on sale this year will eliminate the least pleasant aspect of the 3-D viewing experience—those often uncomfortable and frequently silly-looking spectacles. 3-D TV for the naked eye does not exist—at least not yet. The coming first-generation 3-D-capable TVs for the most part rely on stereoscopic displays combined with battery-powered, active liquid-crystal shutter system glasses to achieve the effect. These glasses, which look something like the polarized shades handed out at movie theaters, alternately darken and lighten the glasses' left and right lenses, at a speed that is too fast for the eyes to perceive. Meanwhile the TV synchronously displays the corresponding right- and left-eye–specific images. 'Basically, you take a [high-definition] TV and add a liquid-crystal display and modulate the display for the left and right eye," says Pierre Blanche, an assistant research scientist at the University of Arizona's College of Optical Sciences (OSC) in Tucson."