May I ask a really rude, obnoxious and nosy question?

What causes tallin and Seaners' blindness? I've been curious, because I'm assuming there's some kind of genetic link to cause it because it would be just too much of a coincidence otherwise, for a father and son to both be blind by different random causes. But I've never heard of congenital blindness being hereditary, so I'm a nosy wench with biological curiosity.

And if you'd like me to shut up and mind my own business, I won't be at all offended. :)