What is LASIK ?

Laser In-situ Keratomileusis or commonly known as LASIK is a surgical procedure that is used treat a wide range of refractive errors in the eye.

The eyeball, cornea or lens being shaped imperfectly causes refractive errors of the eyes. The three common types of problem resulting from refractive errors are as follows:

1. Myopia or nearsightedness. This condition is where only nearby or close objects appear clear to the eye.

2. Hyperopia or farsightedness. This condition is the opposite of myopia and it is where only objects far away or at a distance are clear to the eye. Commonly elderly people require glasses to read a book.

3. Astigmatism, these are where images are blurred at a distance and near. A combination of the above two conditions.

As indicated above, LASIK is a procedure-using laser that can change the above condition that results in patients seeing clearly. In effective, LASIK eliminates the reliance on glasses and contact lenses and thus increases the individual's safety during outdoor activities or sport. In addition, the 24 hour corrected vision and improved conveniences are achieved with as little as 1% risk of side effects post surgery.

The LASIK procedure

Prior to the operation, anaesthetic is placed onto the surface of the eye to numb and reduce irritation. The eye surgeon then starts with an instrument (Microkeratome) to cut or peel a hinged thin flap of corneal tissue off the outer layer of the cornea or eyeball. The flap is then lifted to the side where the laser treatment can takes place.

The laser is then precisely pulsed to reshape the underlaying corneal tissue. The LASIK procedure uses an excimer laser, which is a new class of UV laser (approved by the FDA). It was originally developed for use in the microprocessor industry and later found its application in vision correction. These lasers have a much higher precision and accuracy that can change the shape of the cornea in the eye. It does this by breaking the intra molecular bonds in the collagen molecules during the laser pulse and thereby improving the way light is focused or "refracted" by the eye.

One pulse of the laser can remove and reshape the internal cornea with an accuracy of +/-0.25 microns. To understand the accuracy of one micron, a grain of salt is about 60 microns and the eye can see particles to about 40 microns. It would take about 200 pulses from an excimer laser just to cut a human hair in half. Once the corneal is adjusted, the flap is laid back to the original position prior to the cut and serves as a protective layer during the healing process. The whole process takes only 15 minutes for each eye, which is why LASIK has become popular.

After the procedure, the healing takes place quite rapidity as the cornea bonds quickly. Healing can vary from three days to a week with a final clear vision obtained. Your are now ready to view and see the whole world without glasses or contact lens. To find out more news on LASIK I suggest you visit some online LASIK sites.

by Virginia Wong