Our eyes help us understand the world around us. Revealing a lot About our inner world We might imagine To Early symptoms of hearing loss.
Curiously, our eyes also change when we breathe: In a new study, Swedish and Dutch researchers discovered that our pupils fluctuate in size every time we inhale and exhale.
For over 100 years, it was believed that the pupils responded to more than just light, but these shallow Black Hole The expansion and contraction caused by breathing are contradictory.
Several Research suggests When you breathe in, your pupils dilate, 2022 in review It found that there was “no conclusive evidence” of the phenomenon.
So neuroscientist Martin Schäfer of Sweden’s Karolinska Institutet and his colleagues set out to understand the limitations of previous research. In a series of experiments, the team used special cameras to measure the pupil size of more than 100 volunteers at rest and while they performed visual tasks.
“Pupillary size was consistently smallest at the start of inhalation and largest during exhalation,” the researchers wrote. Write in a reportcurrently waiting Peer review.
The same pattern was seen when the volunteers performed simple visual tasks, or simply stared at a spot, or breathed through their nose or mouth.
This contrasts with previous research that found that pupils are smallest when we exhale. But because pupil size has many different effects, it took Schaefer and her team several breathing cycles to realize that the pupils were subtly aligned with the human breathing cycle. This is because Past contradictory results.
“Is this just a relic?” Schafer I told Michael Le Page New Scientist“Or does it serve some purpose? I’m not sure yet.”
But researchers have some theories about the size of the dancing pupils: Previous studies have suggested that smaller pupils are better at distinguishing fine details, while larger pupils are better at detecting faint stimuli.
“Our findings suggest that vision itself may cycle between optimizing discrimination during inhalation and detection during exhalation within the same breath.” write Schafer and team.
Pupil size also changes depending on emotional states (for example, pupils dilate when you feel fear). Physical excitementand drugs (e.g. (enlarges in response to antidepressants).
Doctors use the pupils to Awareness and Detecting mental illnessTherefore, a deeper understanding of these behaviors will make them stronger diagnostic indicators.
Scientists recently The mechanism was identified The theory behind at least some of these changes is why many of these changes occur, in the same way that pupil size adapts to the breathing cycle. Remains a mystery.
This study has been uploaded BioRxiv Awaiting peer review.
