Testing Web Sites with Eye-Tracking
http://www.uie.com/articles/eye_tracking/

Schroeder, Will
User Interface Engineering
1998

Abstract:

Thanks to some recent usability studies we conducted using an eye-tracking system, we now have real evidence of where users actually look when they view a web page. It’s clear that users quickly learn to look where they expect to find content. They also quickly learn to avoid areas where they don’t see—or expect—what they’re looking for, including banner ads and parts of the page outside the central area.