Ruth relates to my experiences. And as a person with an acquired impairment, I am guessing that she notices a huge difference in the "before" and "after" first encounters with people.
I have grown up with cerebral palsy, and I am used to people staring at me from a distance, people looking away from me as if they might "catch" what I have, people talking to my friends or family as if I'm not there, and people looking at me with pity and sadness. Even though I am used to it, it still makes me angry, and I get tired of all the energy I have to put into "proving" that I am a real person. Still, I try not to let it get to me.
Ruth has some good suggestions. If you are uncomfortable with people who look different than you, I hope you'll check out Ruth's post. I hope you'll find it helpful.