understanding the eye tracking

- Source: American Academy of Ofthalmology
The eye tracking is one of the most promising alternative communication technologies for people with communication limitations. This gaze tracking technique estimates, through video images of the eye of the user, the position observed by the wearer's eye, based on the recognition of a specific characteristic of the eye, such as the pupil.
The EyeSpeak works by identifying the pupil using an infrared light source which is placed away from the optical axis causing the pupil to appear darker than the iris.