and the untreated part of the cornea which bends and distorts the light as it enters the eye. Seeing halos or starbursts usually occurs during night, when the pupil dilates and the edge of the cornea falls right into view and for this reason, people with exceptionally large pupils should not undergo LASIK. These starburst effects, as ophthalmologists call it, usually go away after a few months.Little research is available on LASIKs long-term safety and effectiveness, but there is information available on PRK. Last year, a review in ophthalmology traced eighty-three British patients who underwent PRK in 1990, and found no serious complications in any of them. This is attributed to the amount of untouched, deep cornea (approximately fifty percent of the entire cornea), which maintains the eyes original overall shape. This is opposite of RK which left only 10% of the untouched cornea (Voelker, 1494).Despite its increasing popularity, LASIK is not for everyone. People with extra-thin corneas are not good candidates of this surgery because the surgeon does not have enough tissue to work with. Ophthalmologists also turn away people who have rheumatoid arthritis and diabetes because they have problems with dry eyes, and are hence poor healers. As people approach forty years old, they begin to lose the ability to change their focus from far to near (presbyopia), but dont worry, it is natural in everyone. Baby boomers who have LASIK to try to correct presbyopia, usually trade their distance glasses in for reading glasses (or vice versa). Surgeons are now answering this problem with mono-vision, which is correcting one eye for far distance and the other for focusing on close distances. After this procedure, the brain adapts, using each eye for different functions; however, patients often experience blurry midrange vision and have depth perception problems. Most patients dont mind it, but it drives some people nuts, says Dr. Slade.Ther...
