How Should I Respond? Comments Welcome

I am so proud to be with Mitchell when we go out. I've learned to be up front with those we meet about his delays for their benefit. Chris and I have had a few awkward moments when someone new says something about wishing their child was more calm like Mitchell at that age, only to later feel uncomfortable about pointing out Mitchell being atypical. It's just easier for all if we break the ice.

I wish I was as comfortable about when strangers glance at Mitchell and say something like, "What a tired little guy" or "Boy, he's tired." Mitchell's eyes don't appear as often a blind person's eyes do, but since he doesn't absorb most of what he sees, he mostly looks down making him look sleepy. (Note: this does let you see just how amazingly long his eyelashes are!) How should I respond to a person's comments that he is tired when I know he's not? I have been finding it hard to let the comment go so I admit to being a little pointed responding, "He can't see very well so he looks down a lot." Since it's fueled by a tinge of bitterness, I know I've made people feel badly. They were trying to be nice.

Being in these situations makes me very attracted to families with a child with a limitation themselves. I am pretty conversational and in the moment feverishly try to think of something warm and appropriate to say. Something I'd want to hear myself because I now know that the world wants to avoid different or stare at different, rather than involve it. All but once or twice have I come up short. If I can't think of what to say, why should I think someone else knows the answer? Thoughts on this welcome.