People who've been wearing glasses since they were a child; how are ya

I've been wearing glasses since I was at least 8. I'm 16 now. Just received my new pair of glasses and the lenses are thick as hell.

I have an on-off fear of my eyesight getting irreversibly worse, and I dunno, I guess i'd like to hear other people's experiences as a form of comfort. Do you guys fear it too, and how much?