I'm not sure it's because of the glasses that your son is acting "weird"
I have a 5 year old son who's in Kindergarden. He is acting the EXACT same way for the past couple of week or so!!!! If I ask him to do his homework, he'll turn around and almost yell "I know! Stop telling me!" Totally weird, out of character behavior.
I am a regular parent volunteer in his classroom, almost a daily visitor, and his teacher says that they are ALL acting that way right now! She thinks it's the feeling of Spring.
When I asked her about MY son, and if she noticed any changes, she said there was a change. My son would always be one of the first one's done with the assignment, but lately he can't seem to concentrate enough to get anything done in the allowed time. She said it almost seems like he's "spacing out" occassionally. I appreciated her honesty, but YIKES!
I've been paying extra attention to him, and I just decided yesterday that I think it might be allergies that is affecting him. This weekend I'm going to try to a few "tricks" on him. But, I noticed in his eyes, that they ARE a little bit "spacey" at times. And "cranky", BOY OH BOY is he cranky off and on.
Anyway, my son is NOT adjusting to anything, yet appears to be acting the exact same way as your son. In your case, I'm sure that he is having some soft of an emotional adjustment to his new glasses. BUT, remember he is also acting like a whole Kindergarden class in Modesto!!! So, it might be something else :o)