Is Lasik more effective on short or farsighted patients?
LASIK is
predominantly a treatment for near/short-sightedness, i.e. blurry vision
far off. While it is possible to treatment certain types of
farsightedness (difficulty with vision up close), LASIK does not directly treat
the most common type (presbyopia). Rather it makes an "end run" around it by
putting the focus of one eye up close and the other far off. LASIK treats only
the cornea, while presbyopia is caused by age-related changes of the natural
lens inside the eye. Furthermore, the beneficial effects of LASIK on
farsightedness are not nearly as long-lasting as for nearsightedness because
the natural lens continues to age, undermining whatever effect was originally
achieved.
