Smart contact lenses (CLs) could offer a way to rapidly detect concussions and traumatic brain injuries. 

Brain injuries can occur when the head collides with another object, or is rapidly jolted forwards. People who engage in contact sports such as boxing or rugby are at particularly high risk. Mild brain injuries or concussions affect as many as 3.8 million athletes each year in the US alone (Langlois et al, 2006).