Zonner SW, et al. - Authors analyzed football players in this prospective case-series study of US varsity high school to investigate the near point of convergence (NPC) response to recurring subconcussive head impacts through a series of repeated computations. They measured head impact frequency and magnitude with an accelerometer-embedded mouthguard while heart rate, and their excess postexercise oxygen consumption were recorded with chest-strap heart rate monitors. They suggested the perturbance of NPC over the long term by subconcussive head impacts.