I don't think if eyesight is a prerequisite for hypnosis. For instance, I heard around that some hypnotists tell their client to look at a clock while doing their work on them.
Sometimes people refer to purity by being clear...

@4 interesting. That really adds a different level of play to this concept. Sure, we can't see, but my mind automatically color codes everything for me. Synesthesia is still color, just inside the mind instead of outside. And I think this question is different for every person, due to the different types of synesthesia, schizophrenia, and other weird conditions. Heck probably even some physical conditions could probably effect how clear the mind is.

I know of a couple of blind hypnotherapists, so I'd say this isn't true. Just another stereotype, though a pretty harmless one, like the supposed fact that all blind people are musical geniuses.

Hypnosis has a long history outside Psychology, where its more of a niche specialization. Flipping through some hypnosis association memberships i've come across all sorts of people who practice it, Hawaiian Witch Doctors, Past Life Regressionists, New Age Health types who peddle stop smoking aids and quality of life, stage magicians etc. So, grain of salt and all that.

As for hightened succeptability, I mean if a sighted person were to close their eye's then they would be reducing the amount of sensory input, which could potentially make them more succeptable. But for a blind person who processes sensory information differently I doubt that would result in any greater suceptability, maybe if they were recently blind perhaps, but generally unlikely. Suceptability or inducing a hypnotic state can involve any number of senses, some hypnotists for example use things like physical objects for blind people when inducing a trance state, specifically because it gives them something to focus on. Other's work with mental visualization techniques, but in some cases that doesn't work either, if anyone recalls my topic on Aphantasia, or the inability for some people to visualize things in their mind. Inducing states like these should always be taken on a case by case basis.

Things like this are irritating not just because their misleading, but that they represent a form of cognitive bias or logical fallacy, and i've heard all kinds of strange things people associate or conflate together. It might seem benign, but put into stressful or authoritative decision making situations it can result in serious harm.

@8, that's a new one, I've never heard that blind people are supposedly godlike beings until you said that. In fact, if the masses are to be believed, blind people are famous for having a chip on their shoulder and refusing help to the detriment of their safety and/or self-esteem, whichever comes first, thus why we apparently have to be ambassadors, and prove that we're normal. I guess that comes full circle in a way, but I've never experienced that thought process quite on the level that you describe. At one point when I was in high school, my mom told me, point blank, that she didn't want me to grow up to be fat, lazy, and useless like the majority of blind people. Of course, that comes from someone who has experience being around us, but still, not only was it totally degrading, it also shows how skewed in the total opposite direction some sighted people's mindsets can be.

I don't know that I believe in hypnosis, and the only way that I could is to have undergone the process, which requires giving up more of myself than I am willing to the process. People could be paid to act, for instance.