He Can Hear, Right?

Ordinarily, I don't feel the need to explain my youngest son's disabilities to complete strangers.  For all intents and purposes it's pretty obvious that (and I don't mean to be crass) there's something "wrong with him".  Without going into alot of details, let's just say that the biggest tip off is that he uses a white cane.  A white cane.  This is the biggest indicator that a person has some degree of blindness.

In spite of this obvious indicator, at least several times a year a complete stranger tries to engage me in a conversation about his blindness.  This usually happens when I'm held socially captive like when I'm standing in line at the store.  Usually I don't mind.  As much. Anymore.  Because sarcasm is one of my spiritual gifts, I have to restrain myself from getting snarky.  It's not that I'm a complete jerk; it's just that I am constantly amazed at the things people will say to complete strangers. The conversation usually runs along these lines (with my thoughts in italics):

Q: So, he's blind and he's so young with a cane.
A: Yes, he's getting along pretty well.  Nice detective work, Sherlock.

Q: But is he completely blind?  I mean can he see shadows or some light?
A: He's what's called "legally blind".  He can see some, but not enough to go without a cane.  WTF difference does it make?

Q: Was he born blind? How did he become blind?
A: He had a brain hemorrhage at birth that damaged the part of the brain that controls vision. Would you like to read his medical records?

Q: So his eyes are OK?
A: His eyes weren't damaged, no.  Yeah, they're OK, they just don't see.

Q: But he can hear, right?
A: He can hear, yes.  Dude, "blind" and "deaf" are not synonyms. He can't talk though.

This last one always gets me and I have to fight to keep myself from laughing.  And I am almost always asked this question.  The reason why it's funny to me is that during this exchange he might cover his ears, laugh at something he's heard, try to get my attention, I have to tell him 'no'.  It's obvious that he can hear.  The only thing I can think of is that being blind must elicit some deep-seated fear in people and they just have to make sure that he 'can hear, too' otherwise it would be total devastation.  Seriously, that's the only thing I can think of.

I realize that it's not everyday you see a young blind child with a cane about town with his mom.  It's an oddity.  People are curious.  Perhaps they feel sorry for him.  I get it, I really do.  But before you think I'm an a**hole filled with snarky comments, please try to understand the situation from my point of view: I have to balance my kid's dignity and his right to privacy with being kind and polite to a total stranger who has absolutely no business knowing my son's medical history.  I really don't like to make people feel bad, but I won't sacrifice my kid's privacy in order to satisfy someone's curiosity.  By the way, I was kidding when I said that sarcasm was a spiritual gift.  It's not a gift.  I had to work at it. 

Dear God, please help me to not be so sarcastic. Please help me to be funny and to have a good sense of humor. Seriously, I need a good sense of humor cuz life is not always funny.  Amen.