Presbyopia is associated with aging. When young, the lens of the eye is soft and flexible. It can change shape (accommodate) to allow people to see objects both close and far away. After the age of 40, the lens becomes more rigid, making it more difficult to change shape to do close work, such as reading. This is the reason reading glasses or bifocals are necessary at some point after age forty.
LASIK surgery is not recommended for people with presbyopia, because the procedure works on the cornea, not the lens, and usually corrects distance vision. If a person nearing the age of 40 were to have LASIK, it is likely that they would need reading glasses even sooner.
Instead of LASIK, presbyopic people have the alternative to undergo clear lens exchange. This procedure is the same as cataract surgery, except that the patient's lens is clear instead of cloudy. The natural lens is replaced with an artificial, accommodating intraocular lens--like crystalens-- that would perform the function of the natural lens.