This demo implements an eye tracker, which is based on detecting the outline of the pupil. Note that the camera has to be very close to the eye for this to work well. To be useful in practice, some sort of prism or tele-lens should be used so that the camera can be out of the field of view. This demo was mainly created as an example of an algorithm that can use a 120 frames/s camera capture mode.
The original eye tracking software used here can be found at http://thirtysixthspan.com/openEyes/software.html