Pupil Dilation

The final column of the eye-tracking data details the pupil dilation. There is no actual ``unit'' representation for this value. Rather, it is a measure that is computed by the Eyelink. Also, its range spans a different amount for each eye-tracked user that is often in the range of 1000 - 8000 units. Since there is such a difference amongst each user, the data is pre-processed to include on the first line a minimum pupil dilation and a maximum pupil dilation. The frame's pupil dilation is then sent directly to the audio and video portions of the program to control a parameter of feedback and saturation respectively.