Researchers at MIT and the University of Georgia developed software that can turn any smartphone into an eye-tracking device. The eye tracker uses machine learning, a technique in which computers learn to perform tasks by looking for patterns in large sets of training examples. The training set includes examples of gaze patterns from 1,500 mobile-device users.
To collect their training examples, the researchers developed a simple application for devices that use Apple’s iOS operating system. The application flashes a small dot somewhere on the device’s screen, attracting the user’s attention, then briefly replaces it with either an “R” or an “L,” instructing the user to tap either the right or left side of the screen. Correctly executing the tap ensures that the user has actually shifted his or her gaze to the intended location. During this process, the device camera continuously captures images of the user’s face.
