Our eyes can tell us a lot about our health. They can help health care providers diagnose things like diabetes, genetic disorders, and cancer.

Our eyes may also help give insight into stroke, according to new research.

A team of NIH researchers found that a chemical called gadolinium given to stroke patients during brain scans can leak into their eyes. The gadolinium causes certain parts of the eyes to light up on these scans.

Gadolinium is a harmless chemical given to patients during magnetic resonance imaging (MRI) scans to highlight damage in the brain.

In healthy people, gadolinium remains in our bloodstream and is removed by our kidneys. But when someone has brain damage, it leaks into their brain, creating bright spots.

In the future, health care providers could give a similar substance to patients that would collect in their eyes and quickly tell them important information about their stroke—without the need for an MRI.