To reduce dependency on glasses or contact lenses can have Lasik surgery. The term is synonymous with LASIK Laser Assisted in situ keratomileusis and is a procedure whereby you constantly changing the shape of the cornea. The cornea is the clear covering of the front of the eye.
Doctors use an excimer laser to perform this surgery. A small knife, called a microkeratome, is used to cut a flap in the cornea. A hinge is left at one end of this component. The flap is folded back revealing the stroma, the middle section of the cornea. The pulses from a computer-controlled laser vaporize a portion of the stroma and the flap is replaced. Other techniques are also in use.
The cornea is a part of the eye that helps focus light to create an image on the retina. The bending and focusing of light is also known as refraction. The shape of the cornea and the eye are usually not perfect and the image on the retina is out-of-focus (blurred) or distorted. These imperfections in the focusing power of the eye refractive errors. There are three main types of refractive errors: myopia, hyperopia and astigmatism. People with myopia, or nearsightedness, have more difficulty seeing distant objects as clearly as near objects. Persons with hyperopia, or farsightedness, have more difficulty seeing near objects as clearly as distant objects. Astigmatism is a distortion of the image on the retina caused by irregularities in the cornea or lens of the eye. Combination of myopia and astigmatism or hyperopia and astigmatism are common.
Glasses or contact lenses are designed to compensate the imperfections of the eye. Surgical procedures aimed at improving the focusing power of the eye are called refractive surgery. With LASIK surgery, precise and controlled removal of corneal tissue by a special laser reshapes the cornea changing its focusing power.
Before Lasik, there were other techniques developed to reshape the cornea for example photorefractive keratectomy. Often the exact same laser is used for both types of surgery. The major difference between the two surgeries is the way the stroma, the middle layer of the cornea, is exposed before being vaporized with the laser. In PRK, the top layer of the cornea called the epithelium, is scraped away to expose the stromal layer underneath. In LASIK, a flap is cut in the stromal layer and the flap is folded.
Can anyone have LASIK surgery? Most but not all and some complications are unavoidable in a percentage of patients, and there is no long-term data available for current procedures. In addition, some jobs prohibit certain refractive procedures so be sure to check with your employer / professional society / military service before undergoing any procedure.
Most medical insurance will not pay for refractive surgery and the cost is still important. If you have what is called refractive instability, such as youth, you can not have this kind of surgery. If you are pregnant or have certain diseases like diabetes or are taking medications you should not have Lasik surgery. In these cases, you should discuss the possible additional risks with your doctor.
