A guide to laser eye surgery

Laser eye surgery is a revolutionary technology that can partially, or totally, eliminate your dependency on glasses and contact lenses. The procedure is done on an out-patient basis (so you can go home the same day) and people normally return to work within a week. Laser eye surgery produces permanent results and enables millions of people to throw away their specs every year, bringing aesthetic and practical benefits to everyday living.

This article on eye laser surgery is written by Jackie Griffiths, a freelance journalist who writes health, medical, biological, and pharmaceutical articles for national and international journals, newsletters and web sites.

How the eye works

At the very front of your eye there is a thin, transparent surface called the cornea, a curved structure that provides most of the eye’s focusing power. This is helped by the lens, which sits behind the iris (the coloured part) bringing light rays into even sharper focus before they land on the retina at the back of the eye. The retina captures images upside-down, and sends them to the brain for processing.

If the cornea or lens start to change shape, perhaps due to the natural aging process, it can cause unfocused or blurry vision. This elongation of the eye is thought to be hereditary, causing people to develop myopia (short-sightedness) or hyperopia (long-sightedness) over time.

Both of these conditions require corrective lenses, either for specific tasks (like reading, driving, or watching TV), or throughout the day for general use, to enable people to live their lives in full focus. To begin with, many people opt for spectacles or contact lenses, or a combination of both. However, eye laser surgery is a hi-tech alternative that could free you from this burden forever.

Types of laser eye surgery

While you may have heard of numerous types of laser eye surgery, they each fall into two fundamental categories: LASIK and PRK. All of these eye surgery techniques are based on the same principle of numbing the eye with anaesthetic drops and reshaping the cornea with a laser while the patient is awake.

LASIK, or Laser-Assisted In Situ Keratomileusis, involves cutting a flap in the front of the cornea and reshaping the underlying tissue with a special laser. Afterwards, the flap is put back in place and left to heal. This technique is painless for most patients, immediately effective, and has the fastest healing rate.

PRK, or Photo Refractive Keratectomy, involves scraping away the outer layer of the cornea and reshaping the remaining surface with a laser. The process relies on the outer layers of the cornea growing back afterwards. PRK laser eye surgery has a longer recovery period and is more uncomfortable than LASIK. However, it doesn’t create a cornea flap and doesn’t penetrate deeply into the cornea – both of which carry additional risks.

LASEK, or Laser-Assisted Sub-Epithelial Keratomileusis, is an advanced version of PRK that uses alcohol in solution to soften and remove the outer layers of the cornea. A laser reshapes the underlying layers before replacing the outer cornea parts removed earlier.

Side effects

There are some common troublesome (but not serious) short-term side effects from laser eye surgery. You may experience one or more of the following:

  • dry eyes as the nerves grow back – this may last for several months and can be remedied with artificial tear supplements
  • glare and halo effects at night – lasting up to a year after severe corrections
  • droopy eyelids
  • hazy or blurry vision
  • scratchiness
  • light sensitivity
  • small pink or red patches on the white of the eye

Depending on the extent of the correction it may be unsafe for you to drive for the first few weeks after laser eye surgery. You should also shield your eyes from the sun by wearing UV protective glasses, at least for the first few months.


Laser eye surgery has already proven completely safe for millions of people. On average, complications from eye laser surgery occur in less than 5% of cases, according to the Royal College of Ophthalmologists. These complications include:

  • infection of the cornea – leading to delayed healing
  • undercorrection or overcorrection of vision – necessitating glasses or further surgery
  • reduction in best-corrected vision – where the new vision is worse than the best vision obtained with glasses before surgery
  • excessive corneal haze – beyond the normal healing process, requiring a second operation (the risk with PRK is higher)
  • regression – where the effect of surgery is lost over time, requiring further laser treatment
  • excessive thinning of the eye wall – causing the eye to lose shape and focus, requiring further surgery

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