Choosing An Eye Tracker
One difficulty in evaluating an eye tracking system is that the eye is never still, and it can be difficult to distinguish the tiny, but rapid and somewhat chaotic movement associated with fixation from noise sources in the eye tracking mechanism itself. One useful evaluation technique is to record from the two eyes simultaneously and compare the vertical rotation records. The two eyes of a normal subject are very tightly coordinated and vertical gaze directions typically agree to within +/- 2 minutes of arc (RMS of vertical position difference) during steady fixation. A properly functioning and sensitive eye tracking system will show this level of agreement between the two eyes, and any differences much larger than this can usually be attributed to measurement error.
Read more about this topic: Eye Tracking
Famous quotes containing the words choosing and/or eye:
“Constantly choosing the lesser of two evils is still choosing evil.”
—Jerry Garcia (1942–1995)
“In short, no association or alliance can be happy or stable without me. People can’t long tolerate a ruler, nor can a master his servant, a maid her mistress, a teacher his pupil, a friend his friend nor a wife her husband, a landlord his tenant, a soldier his comrade nor a party-goer his companion, unless they sometimes have illusions about each other, make use of flattery, and have the sense to turn a blind eye and sweeten life for themselves with the honey of folly.”
—Desiderius Erasmus (c. 1466–1536)