I have also found that some instinct has kicked in at the wrong time. In the past when a person was putting her hand out to me in an affectionate way i instinctively grabbed it with force and stopped it. Then i felt bad, and felt quite shocked within myself.
Wow Lewis, I could've written that word for word myself, you've really hit the nail exactly there.
I actually have this trouble most of the time, because people assume if you have a visual imparement that they not only have the right to touch me unexpectedly, but that they are being helpful.
I'll frequently have someone grab hold of my arm to shepherd me off a train or across a road on a dayly basis.
If a person asks me if I require help, I feel in control and can legitimately say no, but there are those people who don't ask, just assume that sinse I have disfunctional eyeballs I have no right to personal space at all.
On a good day I can simply ignore this, on a bad one I've been known to shove people off with a fair degree of force, where upon I feel guilty, ---- even though i know a person's intentions are primarily directed at a social idea of what a "disabled person" is like, and not to be helpful to me personally, ---- if trying to be helpful to me, people would attribute me with the inteligence to answer a question as to whether I want help or not.
As for physical jokes like the one you describe rily, I can't think of anything more triggering to me, and frankly I might well react the same way.
That was indeed how a lot of my abuse started, unexpected physical jokes which got progressively more serious, and on one occasion at the age of 15 when a teacher tapped me on the shoulder I did turn round and close to sprain her wrist, which earned me a massive yelling at just because of what had happened previously.
People who engage in this sort of humour with no care for the sensativity of the person frankly, are at the least idiots, at the worst directly harmful, sadistic bastards.
While I am also very much against violence, and would never recommend it to anyone, I will say this chap at your work got what he deserved for engaging in that sort of potentially harmful joke with you without any understanding of your own feelings.