Monovision is one option for patients who wish to reduce their dependence on glasses for both distance vision and near vision.
At younger ages, we are able to look from far away to close up without changing glasses. This is called accommodation, and it results from the lens inside of the eye changing shape. However, in middle-age, the lens becomes more rigid and less flexible, and the eye is less able to switch from distance vision to near vision. You may be familiar with holding a restaurant menu farther and farther away from your face in order to read it, since your eyes can no longer focus at near. This loss of near vision is called presbyopia. It is a natural part of the eyes getting older.
Presbyopia cannot be reversed, but there are several options for managing it. The most common solution is to wear reading glasses, to put a lined bifocal in your distance glasses, or to get progressive (no-line) bifocals. However, if you are eager to minimize your dependence on glasses, monovision is another option.
In monovision, one eye (the dominant eye) is corrected for distance vision, and the other eye (the non-dominant eye) is corrected for near vision. In other words, rather than both eyes working together at one particular focal point, each eye has its own focal point. Over time, the brain learns to use the dominant eye for seeing far away, and then it switches to the non-dominant eye for seeing up close.
The benefit of monovision is less reliance on glasses for both distance vision and near vision. However, monovision is not for everyone, and separating the eyes has drawbacks. It takes time for your brain to adjust to monovision. Monovision may make you feel imbalanced. You will have a slight decrease in depth perception. Your night vision may not be as clear as your day vision. And you may experience eye fatigue with prolonged activities at any single distance – in fact, if you spend all day reading a novel or if you plan to take a long road trip, you will probably prefer to have a pair of glasses so that the dominant eye can help with near vision, or the non-dominant eye can help with distance vision.
Monovision is not recommended for professionals who require perfect distance vision as part of their occupation (pilots, truck drivers, etc.), for professionals who require perfect depth perception (carpenters), or for professionals who require perfect balance (construction workers). However, if you do not work in one of these fields and you are interested in monovision, talk to the surgeons at New England Vision to see if this might be a good choice for you.