Eye tracking is a noninvasive technique based on infrared video technology that is used to analyze eye movements. Such analyses might provide insights into perceptual and cognitive capacities. It is a method widely used in various disciplines, such as ophthalmology, neurology, psychiatry and neuropsychology for basic science, but also clinical practice. For example, recent studies on children who were later diagnosed with autism spectrum disorders revealed early abnormal eye movement patterns in socio-communicative settings; children with dyslexia appeared to also have peculiar eye movement patterns, expressed in longer fixation durations and smaller saccades while reading. Current research using eye tracking systems in combination with neurophysiological and brain imaging techniques will add to a better understanding of cognitive, linguistic and socio-communicative development and in the near future possibly also lead to a broader clinical application of this method.