Researchers from the AOVISION Laboratory (https://ao.ukbonn.de/index.html) at the University Eye Hospital Bonn uncover the link between foveal cellular topography and fixational eye movements and their consequence for fine scale vision.

In a recently published peer-reviewed pre-print on eLife on June 28, 2024, a team of researchers from the AOVISION Laboratory at the University Eye Hospital Bonn has provided new insights into the fine mechanisms of human gaze control. This study presents human behavioral data alongside single-photoreceptor resolution imaging to validate a long-standing hypothesis about the limits of human vision.

Using a unique adaptive optics photo-stimulation technique, the researchers were able to overcome the optical blur of the human eye. This advanced method allowed for precise tracking of each photoreceptor cell as it actively moved across the retinal image. For the first time, direct observations were made of what the retina and its photoreceptors perceive at the very center of human vision.

The study’s first author, Jenny L. Witten, discovered that humans can resolve details smaller than what classical Nyquist sampling would predict, which is notably finer than the diameter of a single photoreceptor. The key finding is how the eye drifts across stimuli; all participants exhibited motion patterns that were actively tuned to optimize fine dynamic sampling. This discovery challenges the prevailing view of drift as a primarily random process, showing it is positively exploited by the visual system.

This groundbreaking research sheds light on the intricate relationship between cellular structures in the fovea and the sophisticated control of eye movements, offering a deeper understanding of the fundamental processes underlying human vision.

To read the full pre-print, please visit https://elifesciences.org/reviewed-preprints/98648.

Written by: Dr Michela Barboni, Ph.D