Is there an easier way for the disabled to communicate? How does a 6-month-old baby perceive the world? Where is the most effective ad space on a website?
Eye tracking can be used to find answers to questions like these, as well as many others by measuring a person’s point of gaze (i.e. where they are looking) and determining eye/head position.
The origins of eye tracking are over a century old, but in the last 5 years large technological advances have opened up new possibilities. Modern day eye tracking can be used not only in a laboratory, but in homes, schools, and businesses where it aids in research and analysis and is used for interacting with computers as well as with friends and family.
Simple Idea, Complex Math
Eye tracking works by reflecting invisible infrared light onto an eye, recording the reflection pattern with a sensor system, and then calculating the exact point of gaze using a geometrical model. Once the point of gaze is determined, it can be visualized and shown on a computer monitor. The point of gaze can also be used to control and interface with different machines. This technique is referred to as eye control.
Improving the experience
The main challenges of eye tracking are not only in developing the right algorithms and sensor solutions, which are a prerequisite for a high level of accuracy, but also in the way users interact with a specific eye tracking device. Eye trackers should be able to perform with all types of eyes and account for such things as glasses, contact lenses, head movement and light conditions. Users should also be able to save personal settings and even look away from the eye tracker without needing to recalibrate.
Until recently, different types of eyes required different methods of eye tracking. “Dark pupil tracking” worked better for people with dark eyes and “bright pupil tracking” worked better for children and people with blue eyes. Recently, both of these techniques have been combined to eliminate the need for two separate eye trackers.
Another important aspect in eye tracking is the “track box.” This is the imaginary box in which a user can move his/her head and still be tracked by the device. With a larger “track box”, the user will have more freedom of movement and experience greater comfort.
Multiple Applications
With the right idea there is no limit to the applications of eye tracking. Currently, some of the major uses for analysis are academic research e.g. cognitive science, psychology and medical research; market research and usability studies, such as evaluations of advertising or package design and software or web usability.
Eye tracking techniques can also be used for interaction - people can control a computer and make things happen by just looking at it. Eye control can be used as sole interaction technique or combined with keyboard, mouse, physical buttons and voice.
Eye control is used in communication devices for disabled persons and in various industrial and medical applications.
Future Value
The crude, complex, and highly intrusive eye tracking techniques of the past have been replaced by refined and user-friendly methods that are producing valuable results today and paving the way for the future. Eye tracking and eye control have a limitless future. Areas like personal computing, the automotive industry, medical research, and education will soon be utilizing eye tracking in ways never thought possible.