How LASIK Works
Vision Problems
There are three main parts to the human eye: the cornea, the lens, and the retina. The cornea refracts (bends) light so it can be directed through the lens, onto the retina; giving a clear image. When we experience vision problems these are usually the result of disorders or irregularities of the shape of the cornea. LASIK solves these vision problems by using lasers to reshape the curve of the cornea so that normal, clear, sight is obtained.
Astigmatism:
Astigmatism is the inability to focus clearly at any distance due to an irregular or misshapen cornea. With astigmatism the cornea is shaped more like an football than a basketball, and light rays focus at differing points on the retina, causing blurred vision. LASIK corrects this oval shape, making the cornea more round and achieving clear vision.
Nearsightedness:
Nearsighted people see close objects clearly – but not distant objects. In Nearsightedness the curve of the cornea is too steep, or the eye itself is somewhat elongated, resulting in images being focused in front of the retina. LASIK corrects this condition by flattening the curve of the cornea.
Farsightedness:
Farsighted people see distant objects clearly, however all other objects are blurred. In Farsightedness the shape of the cornea is too flat, or the eye is not spherical, causing light rays to focus behind the retina. LASIK correct this condition by shaping the outer area of the cornea so that it focuses correctly.
THREE STEPS TO 20/20 VISION
- The first step of a LASIK procedure is the creation of the corneal flap, a thin segment of the protective 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 called IntraLase which creates a thinner and more precise flap, and does so in such a way that the tissue can grow back much faster and stronger than the old fashioned microkeratome method.
- 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.
- 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 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 produces more discomfort than an all-laser LASIK procedure.
