Why does this happen when I wear glasses?

I wore glasses for almost 4 years now. For some reason, I get a big headache and my eyes start hurting when I wear glasses now. I asked my doctor for a checkup and my prescription is still the same as my glasses before I asked for a checkup. I'm also near sighted if this helps. So what is wrong? I can't see that far without my glasses either and I don't like the idea of wearing contacts or having laser eye surgery.