Overview
LASIK, also called laser-assisted in situ keratomileusis, laser-based eye surgery commonly used to correct nearsightedness (myopia), farsightedness (hyperopia), and astigmatism.
In the LASIK procedure, a hinged flap is made in the outer corneal tissue (the transparent layer covering the front of the eye) and lifted out of the way to allow an excimer laser (an ultraviolet chemical laser, also called an exciplex laser) to reshape the underlying tissue. Tissue reshaping improves the eye’s ability to focus light and thus relieves blurred vision and reduces dependency on eyeglasses or contact lenses. The natural adherence properties of the replaced corneal flap negate the need for stitches.
Benefits of Lasik
• Improved treatment accuracy
• Increased quality of vision
• Reduced chance of night vision problems, such as glare and halos
LASIK is an ambulatory procedure done in an ophthalmology office or clinic. Numbing eye drops are used. The eyelids are held open so that there is no interference with the laser. The ophthalmologist creates an ultra-thin flap on the front of the eye with a precise automated instrument. The flap is gently lifted and the preprogrammed laser then reshapes the inner cornea to refocus the eye. The flap is repositioned and holds itself in place, healing naturally without the need for any stitches. The laser pulses last on average between 30 and 60 seconds. In all, LASIK takes about 20 minutes to do both eyes. The procedure is without much pain and recovery is quick.
Long-term results
Laser eye surgery offers numerous benefits and can dramatically improve the quality of life.
Most people achieve 20/20 vision or better after the surgery, but LASIK results do vary. Some people may achieve only 20/40 vision or less.
You may still need to wear glasses or contact lenses following laser vision correction, though the prescription level typically will be much lower than before.
If you have mild residual refractive error after LASIK and you want a sharper vision for certain activities like driving at night, prescription lenses with anti-reflective coating often can be helpful.
Also, if you are sensitive to sunlight after LASIK, eyeglasses with photochromic lenses can reduce photophobia for clearer, more comfortable vision.
While LASIK has an excellent safety profile, LASIK complications can occur. These include infection and night glare (from starbursts or halos appearing around lights).
A small percentage of people will need a LASIK enhancement, or “touch up” procedure, a few months after the primary LASIK surgery to ac
Why it’s done
LASIK surgery may be an option for the correction of one of these vision problems:
• Nearsightedness (myopia). When your eyeball is slightly longer than normal or when the cornea curves too sharply, light rays focus in front of the retina and blur distant vision. You can see objects that are close fairly clearly, but not those that are far away.
• Farsightedness (hyperopia). When you have a shorter than average eyeball or a cornea that is too flat, light focuses behind the retina instead of on it. This makes near vision, and sometimes distant vision, blurry.
• Astigmatism. When the cornea curves or flattens unevenly, the result is astigmatism, which disrupts focus of near and distant vision.
If you’re considering LASIK surgery, you probably already wear glasses or contact lenses. Your eye doctor will talk with you about whether LASIK surgery or another similar refractive procedure is an option that will work for you.
Risks
Complications that result in a loss of vision are very rare. But certain side effects of LASIK eye surgery, particularly dry eyes and temporary visual problems such as glare, are fairly common.
These usually clear up after a few weeks or months, and very few people consider them to be a long-term problem.
You also may still need reading glasses once you reach the 40s, due to a normal age-related loss of near vision called presbyopia.
Source
https://www.britannica.com/science/LASIK http://www.lasikthai.com/cms.php?ref=do:read/id:76&lang_id=2 https://www.medicinenet.com/script/main/art.asp?articlekey=7849 https://www.allaboutvision.com/visionsurgery/lasik.htm https://www.mayoclinic.org/tests-procedures/lasik-eye-surgery/about/pac-20384774
