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  • In 1948, Spanish ophthalmologist Jose Ignacio Barraquer Moner was fed up with glasses.

  • He wanted a solution for blurry vision that fixed the eye itself, without relying on external aids.

  • But the surgery he eventually devised was not for the faint of heart.

  • Barraquer began by slicing off the front of a patient's cornea and dunking it in liquid nitrogen.

  • Using a miniature lathe, he ground the frozen cornea into the precise shape necessary to focus the patient's vision.

  • Then he thawed the disc, and sewed it back on.

  • Barraquer called this procedure keratomileusis, from the Greek words for "carving" and "cornea."

  • And though it might sound grisly, his technique produced reliable results.

  • So how did Barraquer's surgery work?

  • Keratomileusis corrects what are called refractive errors: imperfections in the way the eye focuses incoming light.

  • Ideally, the cornea and lens work together to focus light on the surface of the retina, but several kinds of refractive errors can impair this delicate system.

  • In people with myopia, or short-sightedness, a steep cornea focuses light just short of the retina.

  • Those with hyperopia, or far-sightedness, have the opposite problem:

  • Light is focused too far beyond the retina.

  • And in people with astigmatism, the cornea has two different curvatures which focus light at two distances and produce blurry vision.

  • Even those with perfect vision will eventually suffer from presbyopia, or "aging eyes."

  • As the proteins in the lens age, they slowly increase its size.

  • By an adult's mid-40s, the lens is too large to easily change shape and shift focus.

  • Glasses and contact lenses bend light to compensate for these refractive errors.

  • But, as Barraquer's procedure shows, we can also alter the shape of the cornea itself; moving the focal point backwards, forwards, or pulling a divided image together.

  • And thankfully, modern eye surgeons can sculpt the cornea with far less invasive tools.

  • In corrective laser eye surgery, surgeons rely on excimer lasers.

  • These tools are accurate enough to etch words into a human hair.

  • To safely accomplish these ultra-fine incisions, they use a technique called photoablation.

  • This allows the lasers to essentially evaporate organic tissue without overheating surrounding eye tissue.

  • So how does laser eye surgery actually work?

  • The first step is to separate a thin layer from the front of the cornea.

  • This can be done with either a flat, wide blade, or a femto-second laser that produces millions of tiny plasma bubbles to create a plane beneath the corneal surface.

  • Surgeons then lift the flap to expose the inside of the cornea.

  • Guided by the refractive error and the shape of the cornea, the excimer laser robotically sculpts the exposed corneal bed into the correct shape.

  • This process usually takes less than 30 seconds for each eye.

  • Finally, the flap is closed, and its edges reseal themselves in just a few hours.

  • Because the lasering is done on the eyeball itself, it's described as "in situ," or "on site."

  • Its complete name is "laser in-situ keratomileusis," but you probably know it as LASIK.

  • Essentially, this technique carves a patient's contact lens prescription onto their cornea.

  • Like any surgical procedure, LASIK comes with certain risks.

  • Some patients experience slightly blurred vision that can't be corrected by glasses.

  • But the technique is currently about as likely to damage your eyes as wearing daily disposable contact lenses for one year.

  • Today, a technique called SMILE enables surgeons to sculpt the cornea through even smaller incisionsfurther reducing recovery time.

  • And lasers aren't just correcting the three types of refractive errors. This technology can also restore aging eyes.

  • In a technique called Laser Blended Vision, surgeons adjust one eye to be slightly better at distance vision and the other to be better at close range vision.

  • The difference between the two eyes is small enough that most patients can merge their vision, allowing both eyes to work together at all distances.

  • Advances in laser technology continue to make vision correction surgery more effective and accessible.

  • One day soon, Barraquer's vision of a world without glasses may finally come true.

In 1948, Spanish ophthalmologist Jose Ignacio Barraquer Moner was fed up with glasses.

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    Estelle posted on 2020/01/06
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