The applications of eye tracking are diverse, and new innovative uses are popping up all the time. Industries spanning from neuropsychology to video gaming are using eye tracking to gain insight to human behavior or capitalize on the intuitive control that eye gaze permits. Andrew Duchowski, author of the book Eye Tracking Methodology, attempts to organize the wide ranging applications of eye tracking by placing them in two broad categories: diagnostic and interactive.
Scientists are finding the diagnostic capabilities of eye tracking technology to be a novel way to collect data on visual behavior and attention. Eye trackers used for research provide video capture of visual patterns and qualitative data on various oculometrics as subjects view a given stimulus. Video capture can be used as objective evidence for post-trial analysis of observed attentional processes. Video recordings can be analyzed side-by-side with eye movement data to verify point of regard, or eye gaze, of the user. The oculometrics, such as blink rate, pupil size, and PERCLOS (percentage of time eyes are closed) that can be captured by some eye tracking systems, can be used to monitor the physiological state of subjects in a clinical setting. For example, eye trackers can be used to monitor the effects of drowsiness on driving performance in a driving simulator. Duchowski suggests that the diagnostic applications of eye tracking technology are best for the fields of psychology, marketing/advertising, and human factors and ergonomics.
As for the interactive category of eye tracking applications, we are seeing eye trackers being developed as assistive technology devices, for interactive or responsive advertising media, and even some attempts as video gaming and entertainment gadgets. In these applications, the eye tracker becomes an input device that functions with another system designed to respond to or interact with the user. In many cases, these eye tracking systems turn the eye into a pointer; for example, eye trackers for assistive communication enable paralyzed users to control the computer cursor with their eyes. As the advertising industry becomes savvier to the power of eye gaze and visual attention, we may begin to see gaze-contingent billboard advertisements and banner ads.
Do you agree that all applications of eye tracking fit into these two broad categories? Are there any other classifications you would include to characterize the diverse applications of this technology? Share your thoughts in the comment section below!
