Our eyes wander as we read text, and not just in the figurative sense — between a series of rapid motions called saccades, eyes remain still for just 200-300 milliseconds on average. Those movements are rich with subtext — they’re driven by cognitive processes involving vision, attention, language, and motor control — and according to new research from the University of Potsdam, Weizenbaum Institute for the Networked Society, and Leibniz Institute for Agricultural Engineering and Bioeconomy, they’re enough to identify a person pretty accurately.  

A paper published on the preprint server Arxiv.org (“A Discriminative Model for Identifying Readers and Assessing Text Comprehension from Eye Movements“) describes a system that learns to associate eye movement behavior — including scanpaths, or gaze patterns — with individuals.​  

“Identification based on eye movements during reading may offer several advantages in many application areas,” the researchers wrote. “Users can be identified unobtrusively while having access to a document they would read anyway, which saves time and attention.”