Researchers may have cracked the code to the human eye's immune defence.

It appears that T cells, not dendritic cells, are patrolling the cornea and keeping it safe from intruders. 

This groundbreaking discovery, published in the esteemed Proceedings of the National Academy of Sciences journal, is rewriting the rulebook on how human eyes stay protected.

The same University of Melbourne team, led by Associate Professor Laura Downie, Dr Holly Chinnery, and Professor Scott Mueller, last year showed that T cells can combat pesky eye viruses in mice in a study published in Cell Reports. Now, they have taken it to the next level.

The secret is a new imaging technique called "Functional In Vivo Confocal Microscopy" (Fun-IVCM). With this tool, the team captured the T cells in action, interacting with other cells and nerves in the cornea's outermost layer. 

They showed that a significant number of these vigilante cells are T cells, not dendritic cells, as previously believed. 

According to Associate Professor Downie, it means a revolution in the understanding of the eye's immune response. 

By tracking T cells dynamically and observing how they react to inflammation, the researchers have gained unique insights into ocular health.