C.,
It's so neat to see your posting. I just read a book to our boys last night called Freckleface Strawberry by Julianne Moore. Our oldest loves it tremendously. He has been reading it all week long. I feel that it would apply in your situation. The little girl hates her freckles and tries to hide them. By the end, she realizes that everyone likes her for who she is.
Our 5yr old has a friend who just got glasses last year. She is such a gem. Her mom has instilled in her to take them off when she plays and only to wear them when she is in class during school. She has been really good about this. Some of her friends even remind her to take them off. How cute is that.
As far as the taking care of them, when you clean yours or put them away at night, have your son participate with you. He has seen you with your glasses and most likely understands how important they are. By watching you, he will learn by your example.
By the way, my boys have broken at least 3-4 pairs of my glasses when they were little by grabbing them off my face. Once they turned 4, they had realized tha that glasses help me to see and that they are "mommy's specials", don't touch. They have gone to great lengths to make sure that my glasses are put up correctly if I set them down randomly and they don't touch the lenses. Most recently I have begun to try contacts again. They found it confusing that I wasn't wearing my glasses and have commented that I need to put them away in their case so they don't get broken. (Our boys are 5 & 8 now)
Your son will learn by watching you. Take time with him and share Freckleface Strawberry. It just might help him to realize that being different is great.
Cheers