One of your choices with LASIK and PRK is monovision, which is the use of one eye for distance vision and the other for near vision. This option is primarily for patients at least 40 years old who have difficulty seeing well enough to read without corrective lenses.
First, it is important to understand that the need for reading glasses is caused by presbyopia, which is when the lens inside your eye has trouble accommodating (or focusing) from far to near vision. The younger you are, the easier it is for the lens to focus. As we near the ages of 35-50, most of us develop presbyopia as our lenses lose their flexibility.
There is currently no laser treatment specifically for presbyopia. However, laser surgery on the cornea can give you monovision, which compensates for problems of presbyopia in the lens. This may give you the ability to see far away and read up close with out being dependent on reading glasses (but you may still want to use reading glasses as an occasional aid).
In a usual non-monovision LASIK procedure, the surgeon wants your distance vision as close to perfect as possible in both eyes. In a monovision case, the surgeon intentionally undercorrects (if you are nearsighted) or overcorrects (if you are farsighted) your non-dominant eye for near vision while correcting your dominant eye as close to perfect distance vision as possible.
The result is that you use your dominant eye mostly for distance and the non-dominant eye mostly for close up vision. When both eyes work together, the brain naturally select the clearer eye, and monovision makes it possible to repeatedly change the range of focus with constantly having to remove or add corrective lenses.
For some patients, there is an initial adjustment period to get used to the new vision. Other patients love it immediately.
For more information visit the American Academy of Ophthalmology's website.