Monovision - Presbyopia is a natural phase in the life of the eye when the it cannot adjust or focus images at different distances, making it necessary to wear different glasses for distance and near vision.  This generally begins around the age of forty and is not caused by any illness or disease. 

Monovision can be corrected with bifocals (glasses that have focal lengths for both near and distance) or with Monovision which corrects one eye to see distance and one for near.  Monovision is only an option for patients who have LASIK for Monovision surgery or wear contact lenses. You can also try Contact Lens for Monovision

In people over 40, if vision is corrected to 20/20 glasses are almost always necessary for reading up close because the eyes are unable to focus or adjust their focal length.  Most commonly in Monovision the dominant eye is corrected for distance vision.  Patients over 40 must choose to either correct both eyes for distance, which will require them to wear glasses for reading up close, or correct one eye for distance and the other for near.  To help make a decision, in some cases contact lenses can simulate the results.

If you are over 40, or wear bifocals or reading glasses, your LASIK surgeon will want to discuss Monovision as part of your LASIK Consultation in order to make sure you get the best possible results from Laser Eye Surgery.  If you are over 50 and do not wish to have Monovision LASIK, you will most likely require reading glasses after your LASIK surgery.  Patients over 50 who choose to correct both near and distance vision corrected without Monovision, an alternative is Lens Replacement Surgery Laser Technology for LASIK.