Is there any limit (power range) for Lasik surgery for eye?
Yes, definitely. The limits to LASIK and many of its risks are directly related to how high a prescription (the refractive error) you need to treat. Laser Vision Correction is generally best for low to moderate degrees of nearsightedness (myopia) and astigmatism. In my experience, most nearsighted people (called "myopes") think their myopia is far worse than their actual glasses prescription indicates! Still, trying to treat more than around -7 diopters of myopia has been shown to be associated with a significantly higher incidence of complications than lower prescriptions. In North America, as based on contact lens sales, an Rx around -3 is the mid-point of the myopia Bell Curve. Over 90% of all myopes in Canada and the U.S. have a less than -5 diopters Rx.
Astigmatism greater than about 4 diopters is only rarely encountered in a structurally normal eye, a very important consideration of good patient candidacy. On the plus corrective lens side, LVC is not so reliable. These cases are hyperopia (a farsightedness sometimes affecting distance vision) and presbyopia, the age-related farsightedness that is not curable with LVC. Even in the case of a good hyperopic candidate, LASIK and its laser cousins cannot reliably treat over about +3 diopters.
_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic