How LASIK Works
LASIK addresses common vision problems by using lasers to reshape the curve of the cornea and solve ‘refractive error’.
What Is ‘Refractive Error’?
In normal vision, the cornea refracts or bends light so it focuses properly on the retina. Nearsightedness, farsightedness and astigmatism are the result of irregularities of the shape of the cornea, or errors in the cornea’s refractive power, resulting in blurred or distorted images being received by the retina. This is termed ‘refractive error’ and can vary from person to person.
3 Steps from “Refractive Error” to 20/20 Vision
1. The first step of a LASIK procedure is the creation of the corneal flap which is a thin segment of the outer layer of the cornea. In the early days of LASIK, an instrument called a microkeratome, a hand-held spinning razor blade, was used to create the corneal flap. With all-laser LASIK this step is performed with a special laser to create a thinner and more precise flap that enables faster healing and a more comfortable patient experience.
2. Next, a different laser is used to re-shape the underlying corneal tissue to correct any irregularities. This step in Custom LASIK is based on an individual 3D map taken of the eye so the most precise corrections are possible.
3. Finally, the flap is folded back into place where it bonds quickly. Healing is rapid with all-laser LASIK, and most people can return to work the next day.
The actual LASIK procedure takes just minutes per eye. You can expect to feel no pain at all, and perhaps just the slightest sensation of pressure. Inserting or removing contact lenses – or just rubbing tired eyes from wearing glasses – produce more discomfort than an all-laser LASIK procedure.
Key Questions About The Technology Behind The 3 Steps
What Is All-Laser or Blade-Free LASIK?
All-laser LASIK is the most advanced evolution for the flap-creation step. In the ‘bladeless’ or ‘all-laser’ technique, a laser forms a series of bubbles in the corneal tissue to create the flap rather than using a blade. The advantages with this advanced technique are more accuracy and stability and greater patient comfort.
Which Technology Solves Night Vision Problems?
Many of us suffer from night-vision problems with or without refractive surgery. In the earliest days of laser vision correction, some patients reported halos and ‘star bursts’ after their procedures, especially when driving at night. Patients with large pupils were more susceptible to this complication.
Today’s advanced lasers such as the Wavelight EX500 have dealt authoritatively with night vision issues. In fact, the Wavelight EX500 may be the best news possible for people concerned about their night-time vision. In FDA clinical trials for Wavelight EX500, patients reported improved night vision after the procedure.
How long does LASIK last?
The refractive errors corrected by LASIK stay corrected for the rest of your life. Since the cornea is living tissue, there can be minor fluctuations and the occasional need for an enhancement as the cornea adapts following the procedure. These are a normal part of the post-operative process.
After the post-operative processes are complete, you can expect your vision to improve and stabilize. After the procedure many LASIK patients report excellent vision that gets even better in the following months and years.
Your eyes will age as you do, and for most of us after 40 another element of the eye will cause vision trouble; this element is your lens. The eye’s lens will gradually lose flexibility and result in a condition called presbyopia, or the need for reading glasses. Monovision LASIK can help this condition significantly.
By the time you are in your 70s you will be experiencing another set of age-related vision problems which LASIK doesn’t address. However, depending on the age at which you have your procedure, you can expect decades of excellent vision free of the effects of refractive error.