I'm sorry, it might be partly that I'm in a bit of a bad mood or something for whatever reason, but I don't know how to read that last paragraph except as:

most of the time, civilisation causes these problems, so I can ignore them, even though they'd still sometimes come up, and even though the specific example was just that - an example.

Unless by "most sicknesses like myopia are caused by civilisation" you mean "most sicknesses that civilisation has answers for" or even "most sicknesses", but I feel like if you're going to make one of those claims, you're probably going to want to back it up.

I also have a question which is probably born of both me misunderstanding and you not communicating perfectly (which, to be fair, can't be expected from anyone :P). If something like glasses is "civilisation" (as your last paragraph says), it seems like that label should extend to other parts of medical technology. If that's true, why aren't you against medical technology (which you said a couple comments up the chain)?