I've been working in usability for several years and have noticed that gaze and pointer movement are usually aligned. This has helped me limit the way hover is used as an event in interfaces to let users get to deeper levels of information in web applications. To illustrate: When Google implemented hover on their image searches to reveal intermediately larger thumbs in search listings, I thought they'd made a mistake; it's largely irritating to have larger images appearing and covering other things one is still viewing as potential targets, as one may not want that information at that point. Users may be simply browsing with their eye and pointer together and pre-empting a click on any one of a number of potential targets.