Wow, this is how conflicts are born, grow and get out of control, all in less than 24 hours.
Basically, Frankiess stepped on a shit as high as a mountain, obliviously making fun of something dangerously delicate, and the thing backfired badly in his face, becase Shawn is extremely sensible to the matter (I don't care if this is right or wrong now, it just is sensible on that). Shawn not-surprisingly got back quite badly, and in terrible fashion, which stimulated Frankiess' pride in nearly the worst way possible.
And now we have two people who are not capable of communicating anymore. WTF.
Well, first of all, Shawn: I understand you felt bad about this, it's really clear after you told your condition's history. But... you know... unless Frankiess knew about this in advance, he hasn't really done anything particularly evil. Lack of tact? Maybe, viciousness? I don't think so. I don't know any past exchanges between the two fo you, but if this is the first time you have problem with him, just get yourself back together and try to elaborate an explication and a request for an apology, not a flaming rant, because after the racist eurofag thing, you can't really expect any possible answer that doesn't include verbal abuses.
Then, Frankiess: yes, you really stepped on an elephant shit. I think (I hope) you didn't know and you didn't mean to, but you did it nevertheless, so I'm afraid it's up to you to be the one who avoids more quarrels and try a reconciliation (which is good, at least on the forum's part). Yes, his reaction was quite out of proportion, but basically it's way more difficult for him than for you to be able or willing to make the first step, and you can't really make a request for anyone else to be a better person than you yourself are, can you? Also, it's not particularly his fault for being oversensible on this matter. it really depends on whether you choose your pride (right or wrong) or the resolution of a contrast.
Note: I am strabic myself and provided with thick glasses.