Not so many years ago, the balls were a lot heavier especially when wet, and in my school days, we still had some balls with laces.
A lace imprint on your forehead would last for hours.
Some players, especially defenders, would practice heading the ball as far as they could on a regular basis.
I think it was in the early 1980s that balls were coated to stop water making them heavier., the old-style footballs also lost some shape during a match.
I wonder if the more modern balls cause less of a problem, and it may be that footballs can still be improved to help this issue.
Footballs in the 1960s had not changed much for many years and were pretty similar to those made in the 1880s it's incredible the level of skill that people like Mathews, Charlton, and others displayed with these old-style footballs
Heading the old style when wet and much heavier was an experience that left you feeling dizzy for short while.
I'm sure modern football helps a lot more, but it's definitely worth investigating the impact of heading in football today.