Masturbation is a normal and healthy sexual activity but an excess of anything can lead to problems. Through the problem of going blind, infertility, low sperm count, erectile dysfunction are just myths with no scientific proof. But, enjoying masturbation more than required can interrupt a person's daily routine, and can also affect their responsibilities and relationship. So you can say that doing anything within the limit is okay, but being addicted to any habit can affect your life, health, and relationship directly or indirectly.