Laser eye correction, also called LASIK surgery, is a surgical procedure that allows people with poor vision to see better without wearing glasses or contact lenses. The Food and Drug Administration (FDA) regulates the sale and safety of laser eye correction devices and procedures. Laser eye surgery is a permanent alternative that has proven effective for a number of vision conditions.
Basics
LASIK stands for laser-assisted in situ keratomileusis, a surgical procedure that changes the shape of the clear covering over the eye, called the cornea. An excimer laser is used for the procedure. The small laser blade is used to cut a flap in the cornea, which is then folded back to reveal the middle layer of the cornea. A computer-based laser then sends pulses to the middle cornea, or stroma, to vaporize this area. The top flap of the cornea is then replaced.
Vision
Laser eye correction is designed to correct the imperfections common in the eyes. The shape of the cornea often is not perfect, which causes distortion or blurring, requiring correction for proper vision. The eyes cannot focus properly, resulting in refractions. The three main types of refraction errors that need correction are myopia, astigmatism and hyperopia. Hyperopia, or farsightedness, results in poor vision for objects that are near, while myopia has the opposite effect and makes objects that are far difficult to see, resulting in nearsightedness. Astigmatism is a distortion of the cornea. By removing the defective cornea tissue, LASIK can restore these vision capabilities.
Risks
The FDA reports that people with shifting vision--such as those who've had a change in their eyeglass prescriptions in the last year, adolescents, women who are pregnant and those with other conditions such as diabetes--are not good candidates for LASIK surgery. People who play sports that are at risk for eye damage such as boxing or martial arts should not receive laser eye surgery. LASIK can be detrimental to those with dry eyes, herpes virus in the eye, those with compromised immune systems and people with thin corneas.
Preparation
Prior to laser eye surgery, contact lens wearers are required to switch to regular glasses for at least two weeks to give the cornea time to resort to its natural shape because contacts slightly change the shape of the cornea. The eye doctor must be made aware of any medications the patient is taking to avoid any complications. The day before surgery, patients are advised to avoid using any creams or makeup that could interfere with the procedure and place the eye at risk for infection.
Surgery
Laser eye correction surgery typically lasts about 30 minutes and is usually performed on one eye at a time. The eye is numbed and held open with a device called a lid speculum. Patients retain vision in the eye during the procedure and are asked to stare at a light to hold the cornea in place while the laser works. Patients usually experience various degrees of blurriness during the procedure. A shield is placed over the eye after the procedure because stitches are not used to hold the replaced cornea flap in place and to protect the eye. The shield is worn until the first post-operative visit, usually within 48 hours.
