<P> During the Original Six era, Maurice Richard and Elmer Lach briefly wore helmets . Jack Crawford wore a helmet to hide his bald head and Charlie Burns wearing one to protect the metal plates in his head from an injury incurred in playing junior ice hockey, predating his NHL career . </P> <P> The death of Bill Masterton from a brain injury in a January 13, 1968 in a game between the Minnesota North Stars and Oakland Seals started to change perceptions surrounding helmets . Helmet use began to gradually increase during the 1970s, with Ted Green being the first Bruins player since Shore to wear one as a result of his NHL career, for the 1970 - 71 NHL season and onwards for the same reason that Charlie Burns had worn a helmet, until Green's retirement from pro hockey in 1979 . The 1972 Summit Series showcased an entirely helmet clad Soviet Union team, with Paul Henderson, Stan Mikita, and Red Berenson being the only Canadians to sport a helmet . Usage increased to the point that 70% of NHL players were wearing them by 1979 . </P> <P> In August 1979, then President of the National Hockey League (NHL), John Ziegler, announced that protective helmets would become mandatory for incoming players in the NHL . "The introduction of the helmet rule will be an additional safety factor," he said . The rule allowed players who signed professional contracts prior to June 1, 1979 to continue to not wear a helmet provided a liability waiver was signed, if they so desired . The last player to play without a helmet was Craig MacTavish, who played his final game during the 1996--97 season for the St. Louis Blues . </P> <P> A visor or shield in ice hockey is a device attached to the front of a helmet to reduce potential of injury to the face . Visors cover the upper half of the face, while full face shields cover the entire face . A series of eye injuries, most notably that to Bruce Fogarty, have led to a call from many to enforce their wearing . As of 2015, 89% of NHL players wear visors . Many other leagues around the world mandate the use of visors . Visors and shields, made of a high impact - resistant plastic, offer better overall vision than the wire cages available, which can obscure vision in certain areas . The face shield provides excellent straight ahead and peripheral vision, but does not provide as good air flow as a cage . </P>

When did helmets become mandatory in the nhl