dear gwenyth,
you are correct that lasik doesn't address the problem of accomodation. with lasik we reshape the surface of the cornea in order to improve the distance vision. after surgery, the patient's eyes will be like any other patient with normal vision, and although distance vision is great, once they reach their 40s the near vision, or ability to accomodate will diminish.
the is the most active area of research at the moment, as there are quite a few baby boomers who would like to be rid of their reading glasses. there are some surgical procedures being evaluated, but they are highly experimental at the moment. unfortunately there are no vitamins or exercises that appear to help with this problem.
currently the way we address this with lasik, is to undercorrect one nearsighted eye to allow some close up vision. if done correctly so that there is not too much difference between the two eyes, most people can tolerate this monovision. often, we will test this with a contact lense prior to the surgery.
i hope this info helps
debra tennen, md