Eye movement-based techniques employed to control HCIs include
Direct Access, Scanning and Eye Commands (gestures). The
system implemented is compatible with all of these techniques
(in accordance with users’ capabilities). However, the most widely
used strategy in vision-based HCI control applications is Eye Movements
Codification. The aim of this technique is to develop control
strategies based on certain eye movements (ocular actions or gestures)
and the interpretation of them as commands. Usually, eye
movement recognition is based on detection of consecutive saccades
in the horizontal and vertical EOG. An initial option selected
in some papers (Gandhi et al., 2010) has been to detect eye movements
using a simple thresholding process, as visual analysis of the
EOG signal (left–right) confirms the occurrence of well-defined