Video technology is behind many eye tracking devices. Cameras produce high-resolution images of our irises, pupils, and scleras. The eyes are illuminated with infrared lights that produce reflections off the corneal surfaces to provide critical geometric information about the orientation of the eyeball.
The image processing function measures the geometric features of the eye elements and computes the spatial positions and orientations of the eyes. This function is an essential part of an eye tracking device.
Using this information, eye trackers project the spatial locations of the eye’s gaze points. When you are looking at a computer screen, for example, the gaze point may be expressed in x,y screen coordinates.
We rely on our vision system to gather data about the environment. Because our eyes can only look at one place at a time, our brains have evolved a strategy for focusing the eyes on the most information-rich objects available. So, our brains direct our eyes to the most important areas in our surroundings from one moment to the next.
Eye tracking technology allows researchers to observe where our brains choose to look. While an eye tracking device cannot explain why our brain chooses to focus on specific things, it can measure and record the sequence of visual pointing decisions the brain makes. We can make inferences about what is important to our underlying cognitive processes with this information.
Learn about our eye tracking device, the Eyegaze Edge® here.