Billboards that know when you're looking at them will soon be a reality, if new eye-tracking gear from a Canadian startup makes good on its maker's claims.

The eyebox2 from xuuk is a palm-size video camera surrounded by infrared light-emitting diodes. It can record eye contact with 15-degree accuracy at a distance of up to 33 feet. A simple glance from a passerby scores an impression, providing a tally that enables new Google-like measurement metrics that real-world advertisers could only dream about until recently.