Refractive surgery is a procedure where ones refractive error is corrected permanently or semi-permanently and thus decrease the dependency on glasses or contact lenses. These procedures can correct myopia (short-sighted), hyperopia (long-sighted) and even presbyopia (loss of reading with aging). The most common method is by LASIK, SMILE or PRK where the cornea is reshaped with laser to allow accurate focusing of the eyes. The other method is by implanting lenses into the eyes or by replacing the natural lens. Ideally these procedures are carried out once the refractive power has stabilized.
LASIK and PRK are techniques using excimer laser to reshape the curvature of the cornea. In LASIK, a flap is created using femtosecond laser (bladeless) or a microkeratome (blade) on the cornea. The flap is lifted and the cornea bed is reshaped using excimer laser. In PRK, no flap is created. However, a minute layer of tissue is removed, prior to excimer laser reshaping. Similar concepts are seen in TransPRK, Epi-LASIK and LASEK. SMILE (ReLEX SmILE) is another non-flap procedure where reshaping of the cornea is done by removing cornea stroma (tissue) with femtosecond laser.
Implanting lenses in cataract patients are among the commonest surgeries in the world. Intraocular lens technology has evolved over the years with more accurate measuring devices and calculations to allow spectacle-free eyesight in patients with healthy eyes after cataract surgery. Not surprisingly it is common for people with minimal or no cataract to opt for the procedure (clear lens exchange) too. The lens technology allows astigmatism correction, presbyopia correction and even both. Finally, a semi-permanent option, is by implanting a lens on top of your current natural lens (ICL). It is seen done more in those not suitable for LASIK and the implanted lens can be removed in the future if needed.