Most men rub themselves to get an erection and to have an orgasm. Masturbation (wanking) leads to ejaculation. Masturbation is completely harmless, no matter how often you masturbate. It won’t make you go blind!
Assuming you’re not spending all of your time masturbating and you don’t masturbate in public places, there is hardly any danger to it at all.
One slight danger with masturbation is infection if you masturbate with something unclean. Also, you may irritate your sex organs by rubbing too hard for too long. If that happens, stop.
It helps you to know your body better, and what you like and don’t like. Of course, you don’t have to do it.