By Linda Conlin, Pro to Pro Managing Editor
Blinking is a natural reflex that protects the eyes from irritants and dangerous objects, spreads tears across the surface of the eye to keep it lubricated, removes dead cells, dried tears and other debris, and sends oxygen and nutrients to the eye. But for all that function, blinking at the average of 14 to 17 times a minute, about 3 to 8 percent of waking hours, is more than needed, and would seem to interfere with visual processing by interrupting input to the retina. However, a new study indicates that blinks are an active part of how we see, not just a mechanism for eye health. (Glance Editorial Team (2024, May 22). Blinking may actually benefit your visual acuity. Glance by Eyes On Eyecare.
Researchers from the University of Rochester found that blinks play an important role in allowing our brains to process visual information. The team tracked eye movements in 12 volunteers and combined this data with computer models and spectral analysis to study how blinking affects what the eyes see compared to when the eyelids are closed. They found that blinking increased the power of retinal stimulation and that this effect significantly enhanced visibility, despite the time lost in exposure to the external scene. Blinking altered the light patterns that stimulated the retina, reformatting visual information and increasing the visual input signal strength for the brain compared to when the eye was open and focused on a specific point. When participants blinked, they became better at noticing big, gradually changing patterns during both voluntary and involuntary blinks. “Neurons respond strongly to temporal changes in their input signals and tend to not respond to unchanging stimuli,” says Bin Yang, the first author of the paper, “Eye blinks as a visual processing stage,” published in the Proceedings of the National Academy of Sciences.
With other senses, body movements help the brain understand space. Researchers previously believed seeing was different, but this research lends support to the idea that vision is more like the other senses. Similar to eye movements, blinking acts as a step in visual processing that uses motor behavior to reformat visual information into the temporal domain. According to Yang, “… blinks make the visual system respond strongly to the image on the retina. Thus, contrary to common assumption, blinks improve—rather than disrupt—visual processing, amply compensating for the loss in stimulus exposure.”