Does the vision quality of the two eyes need to be the same? What if it's not?

You do not necessarily need to have the same visual acuity or refractive error (glasses Rx) in both of your eyes, although that is usually the case.

A common strategy to deal with presbyopia is something called "monovision." This is where one eye is corrected 100% for distance and the other is either left (or made) a little nearsighted so that it can do the close up reading. But this deliberately creates an imbalance in visual acuity that most people, fortunately, are able to adjust to.

_Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic