Scientists at Lancaster University have created advertising screens which track your eye movement as you shop, offering adverts relevant to what you're looking at and eye-controlled interactive displays.

SideWays
The system requires no calibration and can be used to scroll through products on a shop screen.

By monitoring the eye movement of passers-by, the SideWays system can offer up adverts it thinks will be relevant to the products shoppers are looking at.

The system was created by Andreas Bulling of the Max Planck Institute for Informatics in Saarbrücken, Germany, along with Yanxia Zhang and Hans Gellersen from Lancaster University.

Beyond monitoring what products shoppers are looking at, the SideWays system can also be used to help users interact with screens without touching them. A demonstration of the technology shows users scrolling through a list of album covers by looking to the left or right of the screen.

Previously able to work with just one person at a time due to calibration requirements, the system has now been tested with 14 users of various height, ages and eye colour without the need for calibration for each person.

The three-man team explains in a detailed paper that SideWays is "a novel person-independent eye gaze interface that supports spontaneous interaction with displays. Users can just walk up to a display and immediately interact using their eyes, without any prior user calibration or training."

SideWays requires nothing more than an off-the-shelf camera and what the scientists describe as "lightweight" image processing software.

On previous eye-tracking systems calibration to each user had been a "major stumbling block" Bulling told the BBC, "because people always have to go through this calibration procedure - it's time-consuming and annoying."

"Eye-tracking is definitely something that is currently a hot topic," Bulling added. "It is really gaining momentum. I fully expect this technology to become available widely in the near future.".

The team's next step is to create a version of SideWays which can track the gaze of multiple people at once, allowing for more complex advertisements or even eye-controlled games.

The recently launched Samsung Galaxy S4 features eye-tracking technology to scroll its screen up when the user reaches the bottom, and to pause video when the user looks away. At CES in Las Vegas last January, Tobii Technologies showed off its eye-tracking technology which can be used to control various aspects of a PC.