To Click or Blink, That is the Question

Eye trackers may replace the mouse on your computer.  An eye tracker is a device that uses projection patterns and optical sensors to gather data about gaze direction or eye movements with very high accuracy. Most eye trackers are based on the fundamental principle of corneal-reflection tracking; eye presence detection, position, identification, movement, patterns; eyelid closure; pupil size and pupil dilation; gaze direction and point. (ebitesblog.wordpress.com)