If someone has a refractive error in the eye this means they have an abnormal shaped eye or cornea, or they have a hardened lens. By having one of these conditions, it means they suffer with visual impairment because the lights rays do not reached the retina at the correct state that a normal healthy eye would let light in. There are various names for the these conditions because it affects people in different ways, these are
Astigmatism (abnormal shaped cornea)
Myopia (being near sighted)
Hyperopia (being far sighted)
Prebyopia (the hardening of the eyes lens)
In total there are 5 different surgical treatments available for refractive eye surgery, which you can see below.
Laser Assisted In-Situ Keratomileusis (LASIK)
LASIK is a laser eye treatment where the surgeon cuts a flap in the corneal tissue and uses an excimer laser in the tissue underneath to remove the damaged tissue near the corneal stroma.
Laser Assisted Sub-Epithelium Keratomileusis (LASEK)
LASEK is another laser treatment, but this treatment uses the laser to permanently remove small pieces of damaged tissue, changing the shape of the cornea.
Photorefractive keratectomy (PRK)
This is a less invasive surgery than LASEK or LASIK eye surgeries and is normally carried out with local anesthetic, which is given in the form of eye drops. The process involves using an excimer laser to remove the smallest amounts of tissue from the external surface of the cornea.
Radial keratotomy and its new surgical variants involve making incisions to the cornea in the shape bicycle spokes using a diamond knife. These incisions alter the shape of the cornea and are effective against myopia.
Thermal Kertoplasty involves making eight to sixteen burn marks around the pupil and inserting a ring of collagen constriction making the cornea steeper in angle. This procedure is a good surgery for some astigmatism patients.
Refractive eye surgery is very safe, but like anything in life there is a risk even if it is only a small percentage.
Delayed healing due to infection can cause discomfort but will generally not last any longer than four year and only affects one patient out of every one thousand plus surgeries.
Under correcting or over correcting the problem in the eye is another slight risk. The surgeon will know what is wrong with your eye and know what needs to be done to correct it, but like anything in life the surgeon cannot predict exactly how your eyes will respond to the treatment meaning some patients need a second surgery or still need some form of corrective lenses.
Because this is a surgical procedure the more common risk is to have sore, dry, eyes that give you pain post surgery.
Some patients also have a slight haze or halo affect when looking at lights; this doesnt affect their vision normally unless they are driving during the night.
The final risk involves high altitudes. When you venture to higher ground it is believed that you may have slight corneal swelling due to the change in oxygen levels, although this is not painful some patients have said their vision changes and becomes poorer.
Image: Saint Louis University