You could of said that in a better way.
Why? There was nothing malicious in his comment. He didn't call you blind nor did he say you were an idiot or anything of the sort. Lol relax man.
Well, I can understand how it can be seen as taunting if your question is met with the counterquestion if it was a trick question, even if it wasn't meant that way.
People have different sensibilities. If we don't know the person we're talking to, we should choose our words carefully and wisely, especially on the net with people from many different nations and cultures. That doesn't mean that we have to weigh every single word, or that we can avoid every possible misunderstanding, but if we learn from the other that we hit a sore point, I think it's better to show understanding and clear up any misconceptions than to tell them they shouldn't feel the way they feel, just because (we think that) we wouldn't in their place.