What is monovision?
Once people reach the “presbyopic age range,” typically in their 40s, it is not possible to see perfectly both far away and up close without glasses. However, it is possible to use contact lenses (or other means) to set one eye to see far away and the other eye to see up close.
This usually comes up for me as an option after cataract surgery. Rather than using contact lenses to set one eye for distance and one eye for near, we use lens implants after cataract surgery for the same purpose. My experience with monovision leads me to say this: some people love it, and some people hate it. That is why we usually like to try it with contact lenses before electing monovision as an outcome of cataract surgery.