You might want to do some internet research on particular injuries.
Ran into an interesting website that markets a protective facemask for players.
http://gameface.com/
The leading cause of facial injuries in children aged 5 - 15??? BASEBALL/SOFTBALL. Being the leading cause of facial injuries I would expect that it is also the leading cause of eye loss/blindness... maybe? I witnessed a beautiful young lady (20 years old) in a softball tournament that got hit in the eye with a batted ball and blinded... a frightful experience for me as I provided first aid. And surely a lot worse for her.