Sunglasses, or a form of them, have been around since the Roman Empire. It is said that Emperor Nero wore polished emerald green gemstones to watch the gladiators fight in 60 AD. Now, it's possible that he really just preferred a green tint to his fighting, but more than likely it had to do with the sun. For a very different reason, judges in China during the 12th century were seen wearing smoke-colored quartz lenses over their eyes throughout trials....