Long, hard stares are nothing new to computer users, particularly when their PCs have crashed or their screens are frozen. In the near future those stares will let us do more than merely convey anger to our silicon friends. Developers of eye-tracking technology—already a tool to help the disabled interact with specialized computers and to let market researchers evaluate the effectiveness of advertising campaigns—have turned their attention to Windows PCs and video game consoles.

At this month's International Consumer Electronics Show (CES), Sweden-based Tobii Technology showed off a sensor- and camera-laden device that works with PCs running Microsoft's new Windows 8 operating system, which is scheduled to roll out on PCs, ultrabooks and tablets throughout this year. Tobii's Gaze interface lets users activate, select, zoom and scroll, assisted by only a few mouse clicks or taps on a laptop touchpad.

The software takes advantage of the PCEye peripheral Tobii introduced in April 2011. PCEye has four LED sensors that emit near-infrared light invisible to the human eye to create reflection patterns on the cornea. Two digital cameras detect the exact position of the pupil and/or iris and calculate where the user's gaze will fall on the computer screen. The first time a person tries the system, the device measures characteristics of that individual's eyes and stores the profile for subsequent use.

Eye-tracking technology readily fits into the design of Windows 8, which arranges desktop applications in large tiles for easily manipulation on tablets, ultrabooks and other PCs using touch, keyboard and/or mouse. With PCEye and Gaze, users can scroll through the tiles using eye controls. When they find the app they want to launch, they stare at that tile and, while holding that stare, click their mouse or tap their laptop's touchpad, says Barbara Barclay, Tobii's general manager of analysis solutions. Whereas the company's focus has been Windows, the Gaze software could likewise be used with Apple's Mac OS and the open-source Linux operating system.

Tobii saved its neatest trick, however, for an arcade game called EyeAsteroids. Players blast asteroids drifting too close to Earth just by glaring at them for a few seconds. Perhaps this is what Superman feels like when he uses his energy-ray vision to reduce objects to smoldering rubble with just one glance.

Several other eye-tracking technologies exist, although none are yet being put to use to interface with mainstream Windows PCs. Tobii is one of more than two dozen organizations in the Communication by Gaze Interaction (COGAIN) Association, an offshoot of the COGAIN project launched in 2004 to help those with impaired motor skills control specialized computers using their eyes. IT University's GazeGroup in Copenhagen, Denmark, for example, is an association member that designs technology to help the disabled type onscreen and even control a wheelchair through eye tracking.

Challenges remain for the further development of gaze-controlled technologies. Tobii is working to reduce tracking and accuracy problems sometimes caused when users wear very thick eyeglasses or bifocal lenses, which can distort the infrared light used to illuminate the eyes. In addition, bright sunlight makes it more difficult for the camera and software to track eye movement outdoors due to the surrounding ambient infrared light. As a team of German researchers pointed out as far back as 2007 (pdf), this would have to be overcome before gaze control is a realistic option for mobile phones. The infrared LEDs and sensors do, however, function properly under most lighting conditions and work even when a user wears sunglasses, according to the company.