Monovision

Monovision is another strategy for eliminating the need for bifocals or reading glasses.  The goal of the treatment is to achieve spectacle freedom while performing everyday visual tasks.  Monovision can be achieved through the use of contact lenses or LASIK for patients who are nearsighted (myopic).

As a result of treatment one eye, usually the dominant one, is focused at distance. The fellow non-dominant eye is focused at near.  With both eyes open, the brain seamlessly picks the image that is best in focus.

For example, when looking at images that are near such as a watch, cell phone or price tags the "near" eye is doing most of the work. While performing tasks that recquire distance vision such as driving or watching TV, the "distance" eye does most of the work.

This strategy is well tolerated by most people but is not for everyone. For this to be successful, careful pre-operative planning must be done which includes:

• Determination of eye dominance, working distance
• Simulation of monovision with loose lens test and/or soft contact lenses
• Planning for treatment of any corneal astigmatism that may be present

Advantages:

• Less costly than multifocal lenses
• Improved contrast sensitivity
• Reduced haloes and glare
• Availability of high contrast (Tecnis)
• Availability of an astigmatism correcting lens (Acrysof TORIC IOL)

Disadvantages:

• May still need glasses for some visual tasks
• Loss of some depth perception