A well-timed blink helps us to look around

Nov 5, 2026, 12:48:46 PM
Caroline Link , Justus-Liebig-Universität Gießen

When did you last blink? Every few seconds, we briefly close our eyes, interrupting our view of the world. Most of the time, we do not notice. What is more, these brief interruptions hardly seem to interfere with our everyday activities. Researchers at Justus Liebig University Giessen (JLU) and the University of Texas at Austin (USA) have identified a strategy that could explain this: people preferentially blink during head movements—when visual information is already less reliable and less important. The study has been published in the journal Proceedings of the National Academy of Sciences. Blinking keeps the surface of the eyes moist and thus helps us see clearly. However, this comes at a cost: estimates suggest that blinking leaves our eyes closed for up to ten per cent of our waking time. Previous studies under controlled laboratory conditions have shown that people can adjust the timing of their blinks to the demands of an experimental task. Much less was known about how we time our blinks in everyday life, when our eyes and head can move freely. To investigate this, Dr. Alexander Göttker from the General Psychology research group at JLU and Prof. Mary Hayhoe, Ph.D. (University of Texas at Austin), analysed the behaviour of more than 80 participants performing two complex, everyday tasks. Participants built models from building blocks or copied pictures using coloured pencils. Their gaze repeatedly shifted between the building instructions or reference picture and their own work. They were free to move their eyes and head and complete the tasks at their own pace. Modern mobile recording technology and computer-based image analysis make it possible to precisely capture and quantitatively describe behaviour even during such complex activities. Across the two tasks, the researchers recorded more than 38,000 spontaneous blinks. The detailed analysis revealed a striking pattern: the faster the head moved, the more likely participants were to blink. The timing also followed a characteristic pattern: blinking was less frequent shortly before the onset of a head movement and more frequent during the movement itself. This suggests that people briefly postpone their natural need to blink: they keep their eyes open while gathering information to plan their next movement, and then use the movement as an opportunity to blink. The coordination between blinks and head movements also varied from person to person. Among participants who generally needed to blink more frequently, blinks and head movements were more strongly synchronized. This pattern suggests that people adjust the timing of their blinks to their individual needs: those who need to blink more often make greater use of head movements as an opportunity to do so. “This coordination of blinks and head movements is a clever strategy,” explains Göttker, first author of the study. “It allows us to combine two interruptions in the intake of visual information in a way that provides an overall benefit for vision.” When we turn our head quickly to direct our gaze towards something else, the image moves rapidly across the retina and becomes blurred. This is comparable to a video recording in which the camera is panned quickly. Since we need to blink regularly anyway, timing this interruption to coincide with periods of less reliable visual information may contribute to a more stable visual impression. Blinking thus emerges as part of coordinated gaze control. The findings highlight a central aim of “The Adaptive Mind” Cluster of Excellence: they show how important it is to study behaviour during natural activities beyond highly constrained and artificial laboratory tasks. In controlled experiments, participants are often required to keep their heads still while looking at a screen. This can obscure how blinking, eye movements and head movements work together. So, the next time you wonder when you last blinked, the answer might be: the last time you moved your head quickly.