A new piece of technology that tracks eye movements after a head injury might be able to detect concussions and determine their severity, researchers say.

The new technology is essentially like a doctor moving a finger in front of a person’s eyes after a hit to the head - except now it's automated, said Dr. Uzma Samadani of NYU Langone Medical Center in New York City.

And the results are reproducible, whereas with the follow-my-finger method, Samadani said, “Each doctor is going to have variability in how well they’re going to be able to assess how well a person is getting better.”

Samadani said she developed the new technology because she needed a reliable way to assess concussions. Accurate diagnoses would improve patients' care, allowing for more accurate assessments of when they could safely return to work or play after a hit to the head, she said.

The Centers for Disease Control and Prevention defines a concussion as a type of brain injury "caused by a bump, blow, or jolt to the head that can change the way your brain normally works."

In her team's study, 75 people who'd been in accidents (but not necessarily head accidents) plus 64 healthy volunteers all watched a four-minute video while their eye movement was tracked by a computer. The computer could tell when their eyes are moving in opposite directions. So-called disconjugated eye movement has been tied to brain injuries for centuries.

People with hits to the head had less ability to control their eye movements, compared to people who had no known injuries, the researchers wrote in the Journal of Neurotrauma.

The computer also detected signs of concussion in some patients without any noticeable brain injury on a CT scan.

Images, like those from a CT scan, "tell you what (the brain) looks like – not how it functions,” Samadani said.

The researchers also found that the severity of symptoms from concussion was tied to the severity of their eye movement problems.

The technology is currently only available in research settings, but Samadani hopes the U.S. Food and Drug Administration will clear it for use by the end of this year.

“I think we’re going to change how we diagnose and define brain injury and concussion,” she said.

Future research needs to focus on other factors that may influence the results of the test, such as alcohol, morphine and sleep deprivation.

“What we’re finding so far is that these things affect eye movement, but in different ways than brain injury does,” Samadani said. “So we’re hoping to tease out the differences.”