Eye movement tests may detect brain changes in military veterans more than a decade after concussion, according to new research.
The study evaluated 78 military veterans, including 38 with a history of mild traumatic brain injury, often called TBI, a brain injury caused by a blow or jolt to the head, and 40 without.
Participants completed a series of eye movement tasks and cognitive tests designed to measure attention, processing speed and self-control.
Researchers at the CU Anschutz Marcus Institute for Brain Health found veterans with previous concussions were more likely to show slower and less accurate eye movements along with lower performance on certain attention-related tasks.
Some differences were still measurable more than 10 years after the injury.
Jeffrey Hebert, associate professor at the CU Anschutz School of Medicine and director of research for the CU Anschutz Marcus Institute for Brain Health, is the study’s lead investigator.
He said: “The eyes are directly connected to brain networks that control attention, information processing and decision-making.
“By studying how someone’s eyes move during a cognitively demanding task, we can detect subtle brain changes that might not appear on a standard bedside exam or brain scan.”
Hebert said eye movements rely on complex networks across several regions of the brain.
Tasks that require individuals to quickly look away from a visual target, or rapidly recognise and verbally identify a viewed object, test not only visual function but also cognitive control.
This includes the ability to focus, suppress impulses and respond quickly and accurately.
Because these processes rely on widespread neural connections, several mild injuries may leave lasting but difficult to detect effects.
“Even when someone feels recovered, their brain may still be working differently behind the scenes, especially during visually demanding tasks and in busy environments,” Hebert said.
“Objective eye movement testing gives us a measurable way to assess these often covert problems.”
The findings could have implications for long-term concussion care.
Standard imaging tools such as MRI scans often appear normal after mild brain injury, making persistent symptoms difficult to verify objectively.
Hebert said: “Cognitively challenging eye movement assessments may provide clinicians with an additional tool to better understand ongoing cognitive concerns and more precisely tailor rehabilitation strategies.”
While most people recover well from mild traumatic brain injury, identifying those who continue to experience subtle effects could improve follow-up care, long-term monitoring and treatment planning.
Although the study focused on military veterans, the results may also apply to athletes, first responders and civilians who have experienced concussions.
Future studies will explore whether incorporating cognitively demanding eye movement tests into routine concussion assessments could help clinicians better identify traumatic brain injury, track recovery and guide treatment decisions.
