The eye never stands still: the eyeball completes rapid and abrupt movements, called saccadic, to bring the object of interest to coincide with the fovea (area inside the macula) and keep it on it for the necessary time. Only the subsequent processing of the brain reconstructs the overall image thus scanned.
The eyes change direction about five times per second. When we look at a face, for example, our eyes move quickly, first exploring the most important features (eyes, mouth and nose), while the less interesting features, such as the forehead and cheeks, are neglected.
