No, that's obviously not obvious, since the person you responded to thought otherwise.
"I" think was obvious
And you are wrong, as noted. If you mean "it was obvious to me", that's a different matter ... but it's also irrelevant.
It isn't always pragmatic to account for the 5% of people who misinterpret what is being said or who aren't able to contextualize because they are stupid. We've all misinterpreted obvious things before. It isn't that big of a deal.
But then it's also obvious that this is an irrelevant argument because other things very much can get worse. It's not like becoming blind would be the primary concern of a non-blind person getting a brain implant.
Yes, this is what I meant.
I can imagine some rather catastrophic negative outcomes from novel new brain surgery techniques, even if the blindness were not somehow made worse.