Monovision: I Don't want to Wear Glasses at All!
Advances in Optometric technology has reached the point where most people who have to wear glasses can now wear contact lenses. In 1972 researchers began working with a technique for adapting soft contact lenses to solve the needs of bifocal glasses wearers. They became very excited about the results and began to fit a large number of bifocal wearers using this system, which is known as "monovision". Since that time, thousands of doctors across the country have adopted this method. Since then, there has been even more technological improvements, including multifocal contacts that supply both eyes with distance and near vision.
"How does monovision work?"
Monovision is a system of contact lens fitting where one eye is focussed more at distance and the other eye more at near. Since it is your brain (rather than your eyes) that interprets what you see, it selectively learns to focus on the clearer image while suppressing the blurry image. This is analogous to television, where the TV camera works like our eyes to record the image and the television set is like your brain where the image actually appears. Your television set picks up all of the stations at once but you selectively turn the dial to choose the particular channel which you want to watch. Similarly with monovision, your brain learns to subconsciously tune in the image that you want to see at any given distance. Bifocal glasses likewise project an image from distance and near into your eyes at the same time. The bifocal glasses wearer learns to concentrate through the bottom half to see objects close up. With monovision, a similar principle is at work, except turned sideways: the patient sees better at near with one side of his vision and better at far distances with the other side. It is not really a radical principle at all-- it is simply DIFFERENT from what people have gotten accustomed to over the last 200 years of wearing bifocal glasses. Monovision is a good example of "mind over matter".
"Does that mean I will be seeing with just one eye?"
No, with monovision, both eyes are constantly being used. The PERIPHERAL vision of the eyes is not really affected much, and in fact it may be enhanced due to the absence of the glasses frame. Both eyes continuously work together because there is no interruption of vision at any given distance. The brain learns to suppress the blurry central vision in the eye that is out of focus.
"Will monovision harm my eyes?"
No. Some people initially have a slight feeling of strain, distortion, or even mild headache. This is not much different from what happens when you get a new pair of glasses, and it goes away in a short time. Since both eyes are constantly being used, the monovision effect does not cause any physical harm to the eye at all. Also, since soft lenses are used for monovision, the comfort of wearing the lenses is extremely good. "How long does it take to get used to monovision?" Some people adapt more quickly than others. On the average it takes about five days for your vision to begin to feel comfortable, and it usually takes about two or three weeks before your vision becomes consistently clear. However, some people need only half this time to adapt, and others will take several months.
"Should I use multi-focals or monovision?"
Your optometrist will help you decide. At Sun City Vision Clinic we regularly fit patients in both monovision and multifocals. Each patients treatment is customized just to them.
Peter Shaw-McMinn, O.D.
Dr. Peter has owned Sun City Vision Center for over 30 years, during which he raised 4 children, including 2 optometrists. Dr. Peter spends much of his time today touring the United States and the world lecturing thousands of optometrists on various topics within our profession.