Despite what you've seen in Monty Python movies or at Renaissance Faires, people in olden days were a lot smarter than we give them credit for. They didn't exactly figure out how to make gold from horse poop (or however alchemy was supposed to work), but they did figure out a few things about our insides and how to make them better.
After all, archeological evidence suggests they were doing things like ...
Life in ancient times probably sucked for a lot of people for a lot of different reasons, one of which was the absence of eyeglasses. Think about it. For most of history, being born with weak eyes was like a death sentence -- the nerdiest death sentence of all. You wouldn't be able to hunt, or read facial expressions, or tell whether that thing in the yard was a woolly mammoth or your mom.
You'll never be Chief of the tribe, young Mole-eye.
And then there were things like cataracts. Even if you were born with spectacular vision, and were perfect in every physical and mental way, chances are you'd get rewarded for your superiority by living into old age and getting cataracts. For those of you without grandparents, cataracts are when the lenses of your eyes kind of cloud over, like a fog made of eyeball. Everything turns into a soft-focus glamour shot, minus the feather boas and piercing stares. Great if you're a porn director, not so great if you're just a person trying to get around in the world.
"The beach no longer has any meaning for me."
Of course, these days they can actually correct cataracts with surgery using state of the art technology, including "a thin ultrasound probe" that "uses ultrasonic vibrations to dissolve (phacoemulsify) the clouded lens." But eyeball surgery seems like the kind of thing that you couldn't even get in 1950, let alone centuries ago.
Actually, as far back as 1000 B.C., the Indian doctor Sushruta developed a procedure for declouding the lenses of the eye. Warning: surgical eye-poking ahead.
The operation was simple, really. Sushruta and his minions would hold you down, then use a curved needle to loosen the lens and shove the cataract out of the field of vision, presumably back into the brain -- because hey, why not? Recovery was just a matter of having your eye soaked in warm butter and bandaged with some naan bread.
Apparently, Dr. Sush's little eye-gouging was so successful and kickass that famous Greeks like Pythagorus and Democritus traveled all the way to India to see it performed. And yet cataract-removal fever didn't spread over to Europe. Either the Western world preferred seeing the world through fog-colored lenses, or else they assumed the whole thing was too insane to be anything but a big, gruesome hoax.