Researchers at the Karolinska Institute in Stockholm and the University of Groningen report a surprising link between how we breathe and how our pupils adjust. The study introduces the pupillary respiratory phase response, a phenomenon where pupil size changes with each breath. Published in the Journal of Physiology, the work adds a new layer to our understanding of the body’s rhythms and could influence vision science and medical diagnostics.
Traditionally, pupil size is known to respond to lighting, focus, and mental effort. The new findings show breathing as a fourth trigger. Pupil size tended to be smallest during inhalation and largest during exhalation, a pattern observed in more than 200 participants across different lighting, breathing methods, and cognitive tasks.
Five experiments support the result. Participants’ pupils fluctuated in step with their breathing cycles, and these fluctuations held steady whether breathing through the nose or mouth or at various breathing rates. Lead author Martin Schaefer notes that the study suggests a closer tie between breathing patterns and visual processing than previously thought, indicating our internal rhythms can influence how we perceive the world.
The discovery points to potential non-invasive diagnostic tools. Just as pupil responses to light help assess certain neurological conditions, disruptions in the pupillary respiratory phase response could signal brain function changes. This could complement existing neurological assessments.
For Thai readers, the study piques interest in how breathing shapes daily perception. In Thailand’s busy urban settings, where visual information is abundant, understanding breathing’s impact on perception could influence tasks requiring sharp vision—such as reading in bright or dim environments or navigating busy streets.
Thai perspectives on wellness align with this research. Traditional practices in Thailand often emphasize controlled breathing to calm the mind and enhance focus. Scientific validation of breathing’s influence on vision resonates with these holistic wellness principles.
Looking ahead, researchers speculate that slight pupil size changes tied to inhalation and exhalation might affect visual performance. Exhalation-linked pupil dilation could help detect faint objects, while inhalation-linked constriction might improve detail resolution. Such insights could lead to new visual training approaches or cognitive exercises that integrate breathing patterns, benefiting those with sensory processing differences.
Practical takeaways for Thailand include mindful breathing as a daily routine. Practices such as yoga or Tai Chi, which coordinate breath with movement, may support general well-being and potentially contribute to subtle improvements in visual and cognitive function.
As science continues to explore how body systems interact with perception, this research underscores the intricate connections underpinning everyday experience. It invites curiosity and mindfulness about how our breathing shapes how we see the world.