What is monovision cataract surgery?

Monovision cataract surgery replaces the natural lens with an intraocular lens (IOL) that corrects for distance vision in one eye and for near vision in the other eye. The brain switches between the eyes as a person’s gaze shifts. This provides clear, glasses-free vision for most activities.

How does monovision cataract surgery work?

In cataract surgery, a cloudy natural lens is replaced with a clear artificial lens called an intraocular lens (IOL). A monofocal lens is the most commonly implanted IOL. It provides clear vision at one focus only, usually distance. 

After cataract surgery, a person with both monofocal IOLs focused at distance would need glasses to see clearly at near. Some people also still need glasses to see clearly at distance because their refractive error was not corrected by the monofocal IOL.

Monovision cataract surgery is one type of refractive cataract surgery. The goal of most refractive cataract surgery is clear, glasses-free distance vision after surgery. However, it can also be used to achieve clear near vision. 

In monovision cataract surgery, one IOL is set for distance, and one is set for near. Your doctor will perform a few tests to determine your “dominant eye.” The dominant eye is typically chosen for the distance IOL, and the other eye for the near IOL. 

After the brain adapts to filtering out the blurry image, this provides clear vision for most activities. Glasses may still be needed for detailed near work or computer work and for night driving.