On August 18, 1967, the Red Sox were playing the California Angels at Fenway Park. Tony Conigliaro, batting against Jack Hamilton, was hit by a pitch on his left cheekbone and was carried off the field on a stretcher, having sustained a fracture of his left cheekbone and a dislocated jaw with severe damage to his left retina. The batting helmet he was wearing did not have the protective ear-flap that has since become standard (partly due to this serious incident).
A year and a half later, Conigliaro made a remarkable return, hitting 20 homers with 82 RBI in 141 games, earning Comeback Player of the Year honors. In 1970, he reached career-high numbers in HRs (36) and RBI (116). However he was eventually forced to retire because his eyesight had been permanently damaged.
Tony Conigliaro continues to be loved and admired by Red Sox fans everywhere; here is a seldom-seen ticket stub to that infamous game.