I was just having a conversation about laser eye surgery with my family and the debate on whether laser eye surgery is safe or not got heated, to say the least. Aiming lasers at the eye sounds really scary but it is a totally safe procedure. The aim of the procedure is to reshape the cornea of the eye in order to restore clarity in your vision. The aim of the procedure is to reshape the cornea of the eye in order to restore clarity in your vision.
The cornea of the eye is the front part of the eye which is transparent and essentially acts as a lens. The cornea as well as the lens in the eye refracts the incoming light and helps focus it onto the retina in the back of your eye. The images our eye see are actually upside down but our brain takes the image and flips them so that you interpret them as the ‘right way round’. Over time, some of us can develop visual problems and our sight can become blurred. One of the primary causes of blurred vision are refractive problems where the light isn’t focused on to the back of the eye well. This includes short and long sightedness as well as astigmatism.
One way this can be fixed is by laser eye surgery. So how does it work? The laser is focused onto the cornea to essentially heat up and evaporate the cells so that the cornea can be reshaped. The cornea has a mild lens effect which adds to the lens of the eye thus helping to correct for refractive errors.
LASIK, SMILE and surface laser treatments are the three main types of laser eye surgery:
Laser-Assisted In Situ Keratomileusis (LASIK) is a procedure that typically uses two lasers. One of the lasers is used to make a small flap in the cornea and then the other laser is used to reshape the cornea. The flap is then placed back over the cornea and left to heal without stitches. Normally an excimer laser is used which is an ultraviolet laser that uses a combination of a noble gas and reactive gas such as fluorine or chlorine (known as an excimer) as the gain medium. Noble gases do not typically react with much, however, when excited they briefly combine and emit electromagnetic radiation in the ultraviolet region. After this, the molecules disassociate and reabsorption of the ultraviolet rays does not occur. The pulses generated last for only a quadrillionth of a second.
Small Incision Lenticule Extraction (SMILE) laser eye surgery is a type of keyhole surgery where a small, self-healing hole is made. Laser pulses from an excimer laser are used to make bubbles that are less than 1/100th the width of a human hair in the cornea. Little connecting tunnels between these bubbles are then made with the laser so that the surgeon can extract the unwanted tissue. Since no flap is made, this procedure has a shorter recovery time.
Surface laser treatments like PRK, LASEK, and TransPRK are treatments which use an excimer laser to remove the ‘skin’ of the cornea so that it can be reshaped and is then left to grow back naturally. Therefore, these treatments typically have longer recovery times. All in all, it is stated that more than 95% of people who have had laser eye surgery are happy with the results.
Original Date: Jan 28 2018