Why Blinking Doesn't Dim The Lights: Study Shows How Brain Works Extra Hard When You Blink
Everyone blinks every few seconds yet the vision remains constant. A new study shows how the brain works extra hard to stabilize vision despite the fluttering eyes.
Blinking is important to cleanse the eyeballs and keep them moist, but a team of researchers found that blinking does more than these. In between flutters, however, the vision is still clear and they do not dim the lights. They set to find out.
In a new study published in the journal Current Biology by researchers at the University of California, Berkeley, the brain works overtime to stabilize the vision and help the person stay focused on what's he or she is viewing. Hence, the brain works extra hard to reposition the eyeballs.
When the eyeballs roll back in the sockets during a blink, they do not usually return to the same spot when people reopen their eyes. The brain now activates eye muscles to realign the vision, providing a clear vision every time.
"Our eye muscles are quite sluggish and imprecise, so the brain needs to constantly adapt its motor signals to make sure our eyes are pointing where they're supposed to," Gerrit Maus, lead author of the study, said in a press release.
To better understand how human eyes handle the interruption of a blink, the investigators recruited a dozen healthy adults to participate in an experiment. They sat in a dim room for long periods gazing at a dot on a screen while infrared cameras recorded the movements of their eyes.
During each blink, the dot moved, one centimeter to the right. While the participants failed to notice the delicate shift, the brain's oculomotor system recorded the movement and learned to relocate the line of vision on the dot. After 30 blinks, the eyes attuned each blink and shifted automatically to the spot they predicted the dot to be.
The new study shows that it is the brain's ability to continuously correct the failure of the eye muscles that explains why the vision does not change even if people blink.