The surprising reason we blink so much more than we need to

Amazing stuff! In a blink of an eye gets a whole new meaning! 😊

"... on average humans blink up to 20 times every minute, or almost 20,000 times a day. Although each blink only lasts between 0.1 and 0.4 seconds, that adds up to around [3% to ]8% of our waking hours spent walking around with our eyes closed. ...

The scientists found that the rapid motion of the eyelid during a blink changes the light patterns that stimulate the retina, sending a different type of visual signal to the brain than the kind sent when our eyes are open and focused on something. In practice, blinking helps people take in the “big picture” of a scene, and notice large-scale, slowly changing patterns. ..."

From the significance and abstract:

"Significance

Humans spend a remarkable fraction of their awake time while blinking. Here, we show that eye blinks are not simply a mechanism for refreshing the tear film but act as an information processing stage. By modulating the visual input to the retina, blinks effectively reformat spatial information in the temporal domain, yielding luminance signals that emphasize low-resolution information about the global structure of the visual scene. We show that human observers benefit from these transients and that this perceptual enhancement occurs independently from motor signals associated with blinks. Thus, contrary to common assumption, blinks facilitate—rather than disrupt—visual processing, amply compensating for the loss in stimulus exposure.

Abstract

... However, blinks also provide luminance transients rich in spatial information to neural pathways highly sensitive to temporal changes. Here, we report that the luminance modulations from blinks enhance visual sensitivity. By coupling high-resolution eye tracking in human observers with modeling of blink transients and spectral analysis of visual input signals, we show that blinking increases the power of retinal stimulation and that this effect significantly enhances visibility despite the time lost in exposure to the external scene. We further show that, as predicted from the spectral content of input signals, this enhancement is selective for stimuli at low spatial frequencies and occurs irrespective of whether the luminance transients are actively generated or passively experienced. These findings indicate that, like eye movements, blinking acts as a computational component of a visual processing strategy that uses motor behavior to reformat spatial information into the temporal domain."

The surprising reason we blink so much more than we need to

Why do we blink so much? (original news release) Researchers find that blinking plays a pivotal role in processing visual information—adding to a growing body of evidence revising our conventional views of vision.

Eye blinks as a visual processing stage (no public access)

IN PLAIN SIGHT: Owen Tu ’25 demonstrates the apparatus used to track eye movements in the lab of brain and cognitive scientist Michele Rucci.

SEEING THE BIG PICTURE: The researchers tracked eye movements in human observers and combined the data with computer models and spectral analysis. They found that blinks emphasize low spatial frequency (SF)—the overall big picture of a scene—and play an important role in allowing the brain to process visual information.