Scientists from the University of Alabama at Birmingham have uncovered a mechanism that explains why humans have such high visual acuity—the ability to distinguish fine details, read small text, recognize faces at a distance, and perceive subtle features of the surrounding world.

The study, published in Nature Communications, sheds light on how the retina and the brain work together to produce ultra-precise vision.

A research team led by Professor Lawrence Sincich found that the sharpest human vision is driven by signals coming from individual photoreceptors—so-called cones. These light-sensitive cells are located in the central part of the retina, the fovea, and are responsible for high spatial resolution.

Until now, scientists debated how “pure” the visual signals sent to the brain really are. Some evidence suggested that individual cones transmit signals directly, while other studies proposed that signals might be mixed with those from neighboring cells, potentially reducing precision. The new study confirms that signals from each individual cone travel along their own dedicated pathway to the brain without mixing with signals from adjacent cells.

When the eye’s optics are optimally corrected (for example, with properly fitted glasses or contact lenses), the visual signals received by the brain match the density of cones in the fovea.

In simple terms, the retina itself is capable of transmitting information at the highest possible resolution, limited only by the physical arrangement of these cells, while the brain efficiently uses this information.

This discovery helps unify previous findings from anatomy, physiology, and visual perception. It explains why humans can distinguish details previously thought to be too fine for the retina to resolve and confirms that foveal cones are the key source of high-resolution vision.

For ophthalmologists and vision correction specialists, the findings highlight the importance of precise optical correction: the retina is always ready to deliver maximum visual detail—if the eye’s optics allow it.