It wasn't long after we figured out that lenses could be used for correcting vision that we also realized they could be used for spying. The first monocular telescope was invented in 1603, and soon, respectable folks were buying them to better see details on the stage at the opera—not at all to discreetly examine the opposite sex. These tiny telescopes, called lorgnettes (derived from the word "to leer or stare") in French, came attached...Continue Reading