The S2 Eye Tracker continues to work effectively even when someone is blinking. Blinking is implicitly compensated for due to the fast re-acquisition times. During a blink the eye is lost, and is then reacquired when the image of the eye returns. Excessive blinking may result in slightly noisier data, since during the closure of the eye the lids may partially occlude the pupil or glint image information. However, this is only for one or two frames, which can be ignored by the fixation detection algorithm.
The video below shows a quick demonstration of an eye tracking study where the subject is blinking excessively. On the right-hand side you see a recording of the subject. The accuracy of eye tracking data remains, and the reacquisition of the eyes after blinking is fine. This is a good demonstration of the S2 Eye Tracker’s capabilities and flexibility in terms of different types of studies, but also with respect to handling different, more challenging test subjects.