Don't Blink

Forget Windows, icons, and your mouse. Your eyes may be the ultimate computer commander.

Rainer Mauth

Envision a PC that lets you trace a series of hyperlinked documents as you glance at the keywords or activate an incoming e-mail message by just looking at the subject line. Researchers at the Heinrich-Hertz research institute (HHI) in Berlin recently demonstrated a gaze-controlled 3-D user interface. It works without inputting traditional explicit commands. "Our current prototype reads users' gazes and reacts before they can utter a command," says Siegmund Pastoor, a project leader at HHI.

Called Blick (the German word for gaze), the system includes an autostereoscopic display that represents objects in 3-D without the user wearing either a head-mounted display or shutter glasses. Built-into-th e-monitor head-tracking and eye-tracking cameras capture a user's gaze.

"The advantage of our system is that users do not need to look at a fixed point on the screen or hold their head in a particular position," says Pastoor. Blick projects the stereoscopic right- and left-eye views into the user's visual field.

Blick's autostereoscopic, free-viewing 3-D display uses direction multiplexing, a display technique that makes different perspective views visible only from specific positions. For each position, the system calculates on the fly both stereoscopic views and projects them together to create the illusion of a 3-D space. Images seem to jump out at you.

To avoid time lags between the head-tracking camera's image capturing and the stereoscopic visualization on the monitor (a typical delay of about 120 milliseconds), the system runs an algorithm to predict the viewer's head position. Thus, the graphics subsystem o ften works with anticipated head positions.

Additionally, an eye-tracking system constantly senses a user's point of fixation (via a cornea-reflex method). The system then simulates the limited depth of focus of the human visual system and makes currently fixated objects on the screen stand out against the environment. Thus, the user can interact with 3-D objects by just looking at them. If you focus on an object for more than 0.1 second, the object may change its shape or pop up new objects. Of course, the system takes time to get used to.

HHI researchers also developed a visual OS (VOS) that allows you to paste together objects, configure applications, and even "visually" program applications in 3-D space, controlled by your gaze. VOS runs on a Silicon Graphics Onyx machine and also allows for live videoconferencing in a virtual 3-D space.

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Eye-Controlled 3-D Display

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The next generation of user interfaces may be in 3-D and controlled by your gaze.

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Only on the Outside

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The current prototype deploys external cameras.