This Gadget Knows When Players Have a Concussion. Will the NFL Take Note?

It’s been known for some time that concussions can do long-term damage to the brain. What’s been harder to determine is when someone actually has one. In the short term, concussions affect the brain’s ability to pay attention and react to stimuli. That’s why a doctor will have a patient suspected of having a concussion attempt to follow his or her finger: The eyes of a person with a brain injury will often jump back and forth as they try to track it.