High-resolution mapping of foveal vision

Human vision critically relies on the foveola, a tiny region of the retina with the highest photoreceptors density. Although it spans only[~] 0.1% of the visual field, the foveola accounts for nearly one third of projections to the visual cortex. Accurate assessment of foveal function is therefore essential for monitoring visual processes and visual health. However, probing this region is challenging because of its minute size and the incessant eye movements that humans perform, even when fixating on a single point. Here, we leverage recent advances in eye-tracking and gaze-contingent display control to develop a visual field test capable of mapping foveal sensitivity with high precision and reliability. Applied to healthy observers, this method reveals substantial idiosyncratic variability both across and within individuals, with peak sensitivity consistently shifted toward the temporal visual field. By enabling high-resolution individualized assessment of foveal vision, this approach opens new avenues for both clinical diagnostics and basic research.