Eye tracking and head tracking devices are mouse emulators. Users control eye tracking devices by moving their eyes...it is best if their head remains still. Users control head tracking devices by moving their head. Both technologies employ cameras which track the desired movements which result in the cursor (mouse or otherwise) to move on the communication device or computer screen. Mouse button clicking is performed through the use of a "dwell" pre-set time or clicking via eyeblink (eye tracking) or external switch (eye tracking or head tracking).