The Lasik procedure is performed on both near and far-sighted people, as well as those with astigmatism. It’s a very quick procedure that requires just a few minutes.
The Lasik Procedure

Either a microkeratome (an instrument used in Lasik) or an Intralase laser creates a very thin circular flap in the cornea.

The surgeon now folds the flap back and removes some tissue from the cornea underneath this flap via an Excimer laser. The Excimer laser is a cool ultraviolet light beam, which removes very thin layer of the corneal tissue to reshape the cornea. The amount of layers to be removed from the cornea is predetermined by a computer according to the required focus of the light through the eye and onto the retina, to achieve the necessary vision.

At the end of the operation (after the removal of the required layers of corneal tissue) the surgeon flips the flap backwards into its previous place, covering the area of the removed layers of corneal tissue. For nearsighted people the target is to flatten the too-steep cornea, whilst for farsighted people the target is to make the cornea more steep, and to correct an astigmatism the surgeon smoothes the irregular cornea into a normal shape.

Before the surgery the physician undertakes an eye examination to determine the health of the eye and the possibility of doing the surgery, as there are some cases where it is risky or impossible to undergo such a surgery. On examination the ophthalmologist uses a refractor and a slit lamp to check the retinal problems, and a tonometer (to determine the intraocular pressure). If the pressure is high it could signify an early sign of glaucoma. He will also check for hydration of the eye to make sure there is no dry eye disease, if  found then this needs to be cured before performing lasik eye surgery.

In addition, a corneal topographer is used to photograph the eye to create a map of the cornea. No-one has a perfectly rounded cornea and the topographer will display any corneal irregularities, the steepness or flatness which the surgeon must correct during the surgery. There are other recently used devices for this step, which are the “wave front” devices. These send waves through the eye to provide a more precise map of the corneal irregularities that affect your vision. The surgeon should ask you about your general health, there are certain specific health problems or medications that may affect the surgery, or result in health hazards. You should inform your doctor about any health problems or medication that you are taking so that he can ascertain whether to undergo the operation, or postpone it to another day. The final decision rests with the surgeon who will be able to judge whether it is safe for you to proceed with lasik eye surgery.