Hi,

Does anyone have any thoughts on eye tracker drift?  I believe this is the term used when over time, sometimes 5 minutes sometimes more, eye tracking loses its accuracy for a person.  I have a significant number of clients who complain about this and they use different eye trackers.  Does anyone have any ideas or tips for dealing with this or an explanation of what is happening.  I would assume it is eye fatigue but sometimes calibration helps and then 10 minutes later, without having moved, the drift starts again.