Sticking glass in your eye is objectively a bad idea. And yet, in the 1800s, there were several highly educated individuals repeating that very action.
If it weren't for them, 120 million people worldwide, myself included, wouldn't have this wonderfully engineered tool for clear vision, invisible to both wearer and admirer.
The design of the contact lens can be traced back to Leonardo da Vinci who, with a bowl of water, kicked off the whole cringe-worthy history. In a manual published in 1509, da Vinci noted that when you stick your face in water, you see things differently. He wasn't really talking about correcting vision at this point, but manipulating the cornea's power is the idea behind the contact lens at its most basic.
From there, it was a natural progression to assume that a tube filled with water smacked directly against the eyeball would do something cool. The problem: Right on top of the eye meant no blinking allowed. Other proposals included tubes held snug to the eyelids with a headband and capsules filled with "animal jelly." None were viable. None saw real-world testing.
Basically, there were a lot of crazy ideas thrown down on paper before anyone attempted to actually follow them through to their sharp conclusion, be it vision or pain.
That changed in 1888 when German ophthalmologist Adolph Fick started forcing fitted blown-glass shells into the eyes of bunnies, the tech's first live test subjects. Fick's design was aimed at helping patients with Keratoconus, a problem that renders the cornea cone-shaped. The glass shells were meant to push the eye flatter, not to improve, say, near sightedness.
It actually sort of worked. With the rabbit testing going well, Fick took the experiment to his own peepers before trying it out on a few other human test subjects.
At the same time, German medical student August Muller was experimenting with glass discs aimed at improving vision-his own, actually. His 1889 thesis recounts that although he could get the lenses fit on his eyes, violent pain kicked in about a half an hour after insertion. But with the short-lived fix, his myopia improved.
Two things to keep in mind about these early glass models: First, the lenses were huge. They were not the small, light things we have today. Instead imagine big glass sheets—about twice the size of current disposables—blanketing even the whites of the eyes. The shape exacerbated problem number two. Glass was the wrong material. Eyes need to breathe. Where every other tissue in the body is delivered oxygen via red blood cells, the cornea sucks in oxygen directly from the atmosphere. "Glass is impermeable to oxygen. If the oxygen doesn't get to the eye, the cornea starts to swell," explains Nathan Efron, professor of optometry at Australia's Queensland University of Technology.
For these reasons, very few people—maybe 500 in the world, estimates Efron—wore early models. Eyes would tolerate, at most, four hours of air-prohibiting abuse. It wasn't until 1948, when optical technician Kevin Tuohy realized by accident that contacts didn't have to cover the whites of the eyes at all, that wearers were allowed some extra hours. While Tuohy was lathing the lens, a recently invented transparent plastic, the part supposed to cover the whites of the eyes dropped off. This left him thinking, Is there a way the smaller lens could actually work? So he polished down the disk's edges and tried the slimmer model himself. To his surprise, it actually stayed put—even after blinking.
The discovery was huge. "It changed the whole history of contact lenses," says Efron. But it was not without problems. First iterations were abrasive to the sensitive cornea, which was obviously not good. The new shape also had a bit of a lift at the edge, which meant lenses popped out at every available opportunity.
Although more hours meant a broader appeal, it took 25 more years and several advancements in materials for contacts to break big.
It was the soft contact lens that did it, and Otto Wichterle was the unlikely inventor. Despite promising results from early experiments with hydroxyethyl methacrylate, a monomer suited to the moisture of the eye, Wichterle was told to stop the project by his employer—at the time Czechoslovakia's Institute of Macromolecular Research. In a quiet act of defiance, Wichterle took his experiments home, forgoing lab equipment for a child's mechanical kit. With the kit he was able develop a spin casting technique that made soft contacts viable. His patent was picked up by Bausch & Lomb, and in 1972 the moveable-and breathable!—lenses hit the market.
Today, 30% of all contacts worldwide are soft daily disposables, and glass ones are non-existent. Next time you pop in your lenses, give a little silent thank you the material is soft and your eyes are in tact. That's more than the bunnies can say about their experience.
Rachel Swaby is a freelance writer living in San Francisco. Catch up with her on Twitter.