Page 23 - The UK Guide to Laser Eye Surgery
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How does laser eye surgery work?
Laser eye surgery uses a beam of ultraviolet light to reshape your cornea
Any operation that corrects the focusing of the eye is called refractive surgery. Laser eye surgery is simply a form of refractive surgery that uses a laser to reshape your cornea - the transparent, curved window at the front of the eye. Adjusting the curvature of your cornea allows light to
be focused correctly onto the retina at the back of the eye. Refractive surgery is the world’s most common elective surgical procedure.
The most popular form of laser eye surgery is LASIK (laser in-situ keratomileusis). During LASIK, the surgeon uses either a femtosecond laser or, rarely, a mechanical device called a microkeratome to create a very thin corneal flap, about a tenth of a millimetre thick. The surgeon then lifts this corneal flap, and uses a second (excimer) laser to sculpt the bed of the cornea.
This procedure can be used to flatten the cornea (to correct short-sightedness), make it steeper (to correct long-sightedness), and make it more symmetrical (to correct astigmatism). When the surgeon puts the corneal flap back, the cornea takes on this new shape.
ReLEx SMILE is a keyhole form of LASIK laser eye surgery. SMILE (which stands for small incision lenticule extraction) differs from LASIK in that the surgeon does not need to create a flap in the cornea. Instead, a femtosecond laser is used to create a tiny tunnel, through which the surgeon draws out a minuscule amount of corneal tissue (less than 1/100th of the width of a human hair). The main advantage of SMILE over other forms of laser eye surgery is that it is even less invasive than LASIK, as no flap is created. SMILE can be used to treat even higher prescriptions than was previously deemed possible, and is often
a preferred option for patients with drier eyes or thinner corneas.
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How does laser eye surgery work?

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