Laser eye surgery – LASIK explained

‘LASIK’ sounds like it refers to some sort of futuristic weapon found in a science fiction novel that has been dwelling on the top shelf at the back of a dusty bookshop for several decades, like Alexey Tolstoy’s The Hyperboloid of Engineer Garin.

Instead, LASIK is an acronym, standing for ‘Laser-Assisted In Situ Keratomileusis’. Admittedly, this does still sound like a laser gun meant to obliterate an alien community on some distant planet but if the terms are broken down we can discover its real meaning.


‘Laser-assisted’ is fairly self explanatory; the procedure in question will involve a laser somehow. But what exactly is a laser? The word has its origins in another acronym: Light Amplification by Stimulated Emission of Radiation. But let’s not get too complicated!

All we need to know is that a laser is a device that emits light; it is particularly useful because it has a unique ability to achieve a high degree of spatial and temporal coherence. In other words it is very, very accurate. Lasers can be focused on extremely tiny spots and so are perfect for use on something as small and delicate as the eye.

In Situ

‘In Situ’ is a Latin phrase which translates literally to ‘in position’. So we can see how our phrase Laser-Assisted In Situ Keratomileusis is gradually starting to sound less like a crazy sci-fi device and more like a sophisticated piece of technology with beneficial uses in the actual word. We have an accurate piece of light emitting technology which is placed in position.


This word is derived from two Greek words: kerat, which means “horn” or “cornea”, and smileusis, which means “carving”. As this indicates, the word keratomileusis refers to the actual procedure the laser is assisting.

The process was developed in the 1950s by the Spanish ophthalmologist José Ignacio Barraquer in Bogotá, Colombia. He is known as “the father of modern refractive surgery”, of which LASIK is a variety. Laser eye surgery is used to correct myopia, hyperopia, and astigmatism – all optical defects which mean the eye has difficulty in focusing on certain objects and commonly known as long-sightedness and short-sightedness.

During keratomileusis, a flap is created in the patient’s cornea by the laser. Next the cornea is reshaped until it has the desired curvature. Last it is sutured; the tissues of the corneal flap are rejoined to the remaining cornea.

This will have corrected the optical problems the patient previously suffered from. Images will be clearer and sharper. The benefits of laser eye treatment are that it is extremely accurate, painless, and has a relatively quick recovery time. It is an innovative process and a popular alternative to glasses which, until the explosion of the contact lens in the 1950s, had previously been the only way available to correct refractive vision errors. Experimentation with surgery on the eye began in the 1980s and has since progressed to become the safer and more accurate procedure that it is today.