The idea of monovision is to correct one eye for the distance vision and the other for close-up vision. In cases where distance vision needs no correcting, just the near-vision eye would be corrected.
Eye doctors started doing this with contact lenses. They made one lens to correct distance vision and the other to correct near vision. When LASIK surgery came along in the late 1990s, some people chose to have one eye corrected for distance and the other for close-up work.
This means that the two eyes don’t work together any more. As you can imagine, this takes some getting used to, but it can be done.
A related experiment was done in the late nineteenth century by George Stratton. He wore special glasses which turned everything upside down, so that he saw the floor where the ceiling would normally be, and vice versa, and all objects correspondingly upside down.
He found that it only took about 3 days to adjust, so that things looked normal again. In other words, things didn’t look upside down, but looked just as they normally do.
Then he took the glasses off and found everything looked upside down again. So again it took him a few days to re-learn and restore his normal vision.
With monovision, one eye is the distance eye and the other is the reading eye. We can learn to automatically use just one eye, the appropriate one for what is being focused on.
The adjustment period is several weeks. Most people who have it done are pleased with the result. Now they can see near and far without any contacts or glasses.
It’s a good idea to try monovision with contact lenses first, to see how well you can adjust to it, and many people do this.
Disadvantages of monovision
- A slight loss of depth of perception
- A slight loss of peripheral vision
- If you need to see extra clearly at certain times, such as for night driving or long sessions with reading or computer work, you might want some reading glasses for those occasions, but will not need them for routine tasks
Advantages of monovision
- You’ll need no glasses or contact lenses most of the time, perhaps ever
- You can legally drive without any vision correction
- The cost is lower than that of LASIK or other laser procedures
- It can be undone
If you have it done and decide you don’t like it, you can have it undone, and your “near” eye corrected for distance. Then your 2 eyes will be working together again but you’ll need to wea reading glasses.