Around age 40, people start to develop presbyopia, or the need for reading glasses. As a person ages, the lens of the eye becomes less flexible so that we have trouble focusing on near objects.
During a monovision procedure, the LASIK surgeon corrects the dominant eye for distance vision and the non-dominant eye for near vision. Typically, the brain easily adapts within one to three months. When the patient looks in the distance, the distance eye is at work. When the patient wishes to read, the eye corrected for near does the work.