We spend ten percent of our waking time winking, but we are barely aware of it. The blink or blink is a very brief interruption of our visual perception. It plays an essential role in lubricating the eyes and provides the brain with minimal but frequent breaks, small unconscious mental breaks , but very restorative. What we did not know until now is that there is a different way to blink and move the eyes. A team from the University of Tübingen in Germany studied the eye movements of eleven individuals using tiny wires attached to the cornea by tracking with an infrared camera. According to their conclusions, published in eLife , they appreciated a type of movement synchronized with the wink that had not been known until now. Apparently, it serves the function of repositioning the eye after the rotation that occurs when viewing a rotating object, as when we try to stabilize the small oscillations of the camera to fix the image. And we are not aware of this repositioning of the eye because it occurs automatically when we blink.
Mohammad Khazali, who has led the research, expresses their surprise at discovering this movement that they had not anticipated at all at the beginning of the experiment. In fact, they proposed to investigate whether the so-called nystagmus exploration , an involuntary, oscillating, spontaneous or induced, repetitive and rhythmic eye movement, characterized by a first phase of slow pendulum oscillation, and a second phase of sudden and rapid spasmodic recovery, it took place at the same time we blinked or winked.
In theory this reflex movement also produces a disruption of the visual system. In the experiment, they tracked the subjects’ eye movement while viewing a rotating pattern of dots or moles. As their eyes rolled trying to track the stitches, they frequently repositioned themselves by scanning the nystagmus to avoid forced movements that would exceed the mechanical limits of the eye muscles. However, this reset did not work at all and the eyes tended to rotate to the limit of the capacity of the eye muscles. The range of rotation varied among the study volunteers between 3 and 8 degrees.
Once they reached the turning stop, the eyes would reposition simultaneously with the blink. Researchers have called this newly discovered mechanical action blink-associated resetting movement (BARM) . According to Khazali, “we can see acutely thanks to the fovea, a light-sensitive area of the retina that needs to be stable to optimally scrutinize objects of interest in the visual field.” The frequency and amplitude of the BARM movement depends on the distance that the eyes have deviated from this neutral position of the fovea.
