(I) There are some inventions such as the wheel and the printing press that have radically changed human existence. (II) Then there are those more mundane things that we rarely think about, but without which we'd be much worse off. (III) Imagine a world without glasses for example. (IV) Probably the oldest eyeglass frames known are recorded in a painting by Di Modena in 13(IV) Many of us would walk around bumping into things and driving our cars up onto the sidewalk.