Corneal Reflection

An eye tracking technique that works by shining a near-infrared light at the eye and measuring the relationship between the reflection off the cornea (the bright spot called the glint) and the center of the pupil. As the eye rotates to look at different screen positions, the pupil center moves relative to the fixed corneal reflection, allowing the system to calculate gaze direction. This is the most common technique used in modern video-based eye trackers for assistive technology because it is non-invasive, works at a distance, and can achieve accuracy sufficient for gaze-based computer control.