ABSTRACT
This chapter begins by presenting the various fields of application of Eye Tracking (ET). It provides the basic physiological understanding of the Human Visual System and especially of the eyes' characteristics that are necessary to consider when performing ET experiments. Taking into account eye movement analysis together with activity and task analysis leads to more accurate design and evaluation of Human Machine Interaction in general, and of visual systems in particular. Visual attention theories are necessary to analyze and understand eye movements. ET is intended to be performed from an "active vision" and "vision for action" perspective. The persistence of vision and the phi phenomenon are essential for the visual response to motion. Both are exploited in television, computer displays, cinema, and graphics. A visual pattern is a structured sequence of several Items of Gaze that repeats identically at least once during the observed period.
