"Monovision" is a technique used to deal with the correction of presbyopia, the gradual loss of the ability of the eye to change focus for close-up tasks, which progresses after the age of 40. This practice was first applied successfully for contact lens wearers, in which one eye is fit with a contact lens to correct distance vision, and the other eye is fit with a contact lens to correct near vision. Similarly, with LASIK, a patient has one eye operated on to correct the distance vision, and the other operated on to correct the near vision.
Patients over the age of 40 who have symptoms of presbyopia have a choice. If both eyes are corrected to see well in the distance, then glasses will be needed for close-up work. The alternative is monovision. Monovision represents a compromise that allows for the preservation of both distance and near vision without the use of glasses. The majority of patients have no difficulties with this procedure, and it is the most common technique requested by eye specialists undergoing laser vision correction. A contact lens trial will always be performed prior to surgery to mimic the monovision effect and determine a patient’s level of comfort.