You get punched in the eye hard enough you can go blind.
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I won’t name it on this family friendly forum but there’s a sexual practice that can cause blindness too.
I once heard that there are two classes of liars in the world:
Those who say they have never done it and those who say, I used to do it but I quit.
Ask a few boxers who have had their careers ended because of retina damage and risk of blindness.