Helmets have changed substantially since their introduction, starting with the "hairnet" designs (https://en.wikipedia.org/wiki/Bicycle_helmet#History_of_design

Helmets have changed substantially since their introduction, starting with the "hairnet" designs (https://en.wikipedia.org/wiki/Bicycle_helmet#History_of_designs https://en.wikipedia.org/wiki/Bicycle_helmet#History_of_desi... also shown in the classic film Breaking Away), better foam/shell materials, fitting, visors that protect the nose from ground contact, and specialization toward different types of cycling. Full-face helmets are used in mountain biking for frontal impacts.