Blinking, or blinking, is an innate physiological reflex that results in the rapid closing and opening of the eyelids. Typically, a person blinks involuntarily every few seconds. At this moment, the tear is evenly distributed throughout the eye, and irritants are also removed from the surface of the cornea and conjunctiva. Scientists have long considered this to be the only function of this reflex. However, a recent study found that blinking increases the efficiency of the brain's processing of visual information. That is, thanks to this involuntary movement, we better assimilate information coming from the eyes.
A person needs blinking not only to moisturize the eyes. Photo source: russtimes.ru
The blinking function is important
The eyes are designed in such a way that they must always remain moist. Otherwise, fatigue and irritation of vision occurs, the eyes turn red and a feeling of “sand” occurs. Therefore, for dry eye syndrome, or keratoconjunctivitis, people are prescribed artificial eye drops, and a few years ago scientists even created artificial lacrimal glands. However, most people do not experience such problems due to blinking.
Dry eyes can lead to inflammation and even blindness. Photo source: masterok.livejournal.com
To prevent your eyes from drying out, you have to blink often. Because of this, the average person spends three to eight percent of their time with their eyes closed while awake. True, we don’t notice this, since blurred vision occurs for a split second.
How blinking affects brain function
Given such a high frequency of closing and opening eyelids, scientists have suggested that this the reflex may also perform some other function, and perhaps influence the processing of visual information. To find out, they conducted a study in which they recruited twelve volunteers – men and women aged about 22 years. All participants in the experiment had normal vision.
People were not informed about the purpose of the study in order to achieve the most objective results. During the experiment, they were asked to look at images of lattice patterns and determine whether the lines were directed clockwise or counterclockwise. At the moment when the volunteers performed the task, the Dual Purkinje Image eye tracker tracked eye movements with high accuracy.
People perform better in visual processing tasks while blinking. Photo source: optic-center.ru
During the experiment, participants in one case had to blink while looking at images on the monitor, and in another case, they had to blink until the image appeared. At the same time, the scientists controlled the timing and conditions of blinking to ensure that the observed effects were associated with blinking and not other variables.
After analyzing the data, the researchers found that when participants blinked while performing the task, they were more effective at identifying the positions of lines in the picture. This effectiveness was reflected in both the accuracy of their answers and their sensitivity to visual details, the researchers report in the journal Proceedings of the National Academy of Sciences.
Why Blinking Improves Brain Function
Human vision is inherently discrete. For example, when we look at one point and examine an object, it seems to us that our eyes are motionless at that moment. But in fact, they make a huge number of movements in small jerks. During each such jerk, a person does not receive visual information, that is, it is as if he is going blind, but the brain itself replenishes it. This can be compared to how we receive tactile information – in order to understand what surface it feels like, we don’t put our hand on it and don’t hold it motionless, but move it along the surface.
During blinking, a sharp change in brightness occurs: Photo source: elitplus-clinic.ru
Thus, through small movements called saccades, the brain seems to scan the image, as a result of which the object we are looking at remains in the zone of best vision. Simply put, without saccades, we would not be able to see objects so well and clearly.
Scientists have suggested that blinking the eyes also provides some discrete vision, which improves the perception of a visual image. During the rapid closing and opening of the eyelids, sudden changes in brightness occur. These changes reset, or reformat, the visual information that enters the brain through vision, resulting in new information being processed more efficiently.
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To test this hypothesis, the researchers conducted another experiment in which they artificially simulated the effect of blinking. That is, they dimmed the brightness, but the experiment participants themselves did not blink. As a result, their visual processing performance was as efficient as when blinking. This means that image processing is influenced not by the eyelid movement itself, but by the “reset” of visual information.