I forgot to double check on this during school today (crazy busy! which is awesome!) so this is from Wikipedia. But I've double checked on a couple of the reference links and they look legitimate.
Glasses in one form or another have been around since about 1000 AD. Early Romans discovered that looking at things through a glass or vase of liquid would enlarge whatever it was they were looking at. Many people give an Italian credit in 1286 for inventing and using the first examples of eyeglasses. By 1301 there were laws about making and selling glasses. It was not until 1604 that anyone could explain WHY thin pieces of glass or plastic seemed to help people see better.
Oh. And another question this week? (Actually ... the ONLY other question. Our Wonders are just starting up and have been pretty slow. :/ But this one made me laugh.)