This wacky idea has its rooted in religion and comes from the days when people thought the only reason for sex was to procreate. One clearly can't make babies through masturbation so to scare people off it, people we told (often by their places of worship) that masturbation causes blindness.
There are other similar myths in this vein: people once told other masturbation could lead to tuberculosis and insanity. Thankfully you'll struggle to find someone who believes any of this in 2018.
Myth #2: People in relationships don't need to masturbate
There's a strange social construct that a person masturbates because they aren't getting enough sex, or aren't satisfied with their sex life. There's also an odd belief out there that masturbating is somehow cheating on your partner. None of this is true.
Almost everyone masturbates, regardless of relationship status. The reality is masturbation can be a completely different experience than sex, and the two are in no way mutually exclusive. It has different sensations, speeds, resulting orgasms, and effects on things like relaxation and stress relief.
Myth #3: Only teenage boys masturbate
Because of sex-shaming and the misogynistic belief that females shouldn't be sexual, many pubescent girls are led to believe that masturbation isn't normal and it's something just for "dirty" and "horny" boys. Not true.
A study from the medical journal Archives of Pediatrics and Adolescent Medicine compared male masturbation throughout teenage years to that in females of the same age, and found that 74 per cent of teenage boys and 48 per cent of teenage girls masturbate.
Myth #4: Masturbation can cause sores or other damage to the genitals
While it is possible to experience minor genital irritation from masturbation – just as there is with sex – this isn't common. You can't damage your penis or clitoris by stroking it, at absolute worst, there's a small risk of chafing or tenderness if your masturbation sessions are prolonged.
It's impossible for masturbation to cause sores, warts, erectile dysfunction, or any similar physical problem. In fact, masturbation only has good health benefits, including better sleep, fewer headaches, less stress, increased self-esteem, and – particularly among older women – reduced vaginal dryness.
Myth #5: You can masturbate too much
There's no magic number for masturbation. Some people do it once or more a day, others once a week or month, and some not at all. Frequency is a completely personal preference. Whatever your choice, it's normal.
Masturbation only becomes "too much" if it starts to interfere with the rest of your life. If it causes relationship problems, it affects you at work, you can't think about anything else, or you're only able to orgasm through auto-stimulation, going on a sort of "masturbation diet" with limited self-touching may help you resolve the issue at, ahem, hand.
Myth #6: Dildos and vibrators mean a (straight) woman isn't interested in her partner's penis
A lot of men are afraid of incorporating dildos or vibrators into sex with their female partners for fear of feeling "replaced". It's true that some women are not able to orgasm through penis-to-vagina penetration, but this is nothing to do with their male partners.
It's also nothing to be ashamed of. Everybody has a different response level, and it's important for men to know that we cannot do what a vibrator can. It produces more controlled, intense, specific sensations. Masturbation with an external device can also help women become more confident and responsive to other types of sexual play. It simply allows a person to experience a fuller range of sexual satisfaction.
Myth #7: Masturbation makes you gay
I'm not even going to go into this one. Stupidest myth ever. Touching your own genitals has no correlation to what genitals you're attracted to. It's like thinking your ability to hold your breath underwater makes you a fish.