Eye-tracking augmented user interfaces

The eye, being simultaneously the mind's window to the world and a world's window to the mind, has many potential applications in human-computer interaction. Two applications I have been involved in are MAGIC pointing (with Ihde and Morimoto) and iTourist (with P. Qvarfordt). I have argued that whenever possible the eye-gaze should be used as a contextual and implicit, rather than a direct and explicit modality of computer input. See an CACM article on eye-tracking, and my keynote abstract and slides at the 2008 ACM Eye-tracking Research and Applications Symposium.