When a young boy in 1970s Russia cut his eye on a shard of his broken glasses, an incredible thing happened: His eyesight improved in the injured eye. This stroke of luck paved the way for the revolutionary vision-correction surgeries we know today.

In a LASIK surgery, doctors improve a patient’s eyesight by permanently altering the shape of the cornea. (The term stands for laser-assisted in situ keratomileusis.) A tiny blade or laser (called a microkeratome or laser keratome) is used to cut a flap in the cornea, leaving a hinge at one end so it can be folded back. The doctor then wields a laser to vaporize a portion of the cornea’s middle section, called the stroma, shaping it to correct vision problems such as nearsightedness, farsightedness, and astigmatism.

Corrective lenses work by changing the angle at which light enters the eye. For much of the 20th century, doctors wondered how they could produce a similar result by changing the curvature of the cornea instead. Japanese scientists in the 1930s attempted corneal incisions, but it wasn’t until the accidental injury of the young patient’s eye in Moscow (the glass merely shaved off a piece of the cornea) that the ophthalmologist Svyatoslav Fyodorov (1927–2000) began to regularly and successfully perform a procedure called radial keratotomy using tiny knives. The American ophthalmologist Leo Bores studied with Fyodorov in Russia and brought the technique back to the United States in 1978.

The first laser-assisted eye surgery—known as photorefractive keratectomy (PRK)— took place in Germany in 1988. A device called an excimer laser produces a cool beam of ultraviolet light that breaks down the carbon bonds in corneal tissue molecules with a degree of safety and precision that was unattainable with traditional tools. LASIK surgery, first approved in the United States in 1998, also uses an excimer laser but does not scrape away outer layers of the cornea as PRK does, so recovery is usually quicker and side effects are less severe. Since its approval, hundreds of thousands of people in the United States have undergone LASIK surgery.

ADDITIONAL FACTS

  1. Some patients experience side effects from LASIK such as double vision, dry eyes, or seeing halos around bright objects.
  2. Between 5 and 10 percent of patients need follow-up procedures to fix over- or undercorrection. Results can also diminish over time for some patients.
  3. Fyodorov apparently became determined to find a way to avoid wearing glasses when he saw the 1973 Woody Allen (1935–) comedy Sleeper. Allen’s character wakes up in the 22nd century surrounded by doctors, one of whom is wearing glasses; apparently even after all that time, no cure for poor eyesight had been developed.