Mike
I opted for single vision. Long range. I figured that I was used to glasses for reading so that would be the same as before.
I have read of the multivision lenses. As I understand it there are two types: one has a bifocal or multifocal arrangement, the other is flexible and the muscles in the eye can move it just as we do (did

) when focussing from far to near objects.
The success rates for the multivision lenses were not encouraging to me. The last thing I wanted was to have to get used to the things over a period of time - I did not have the time; my work involves voracious reading. And I did not want to run the risk of chromatic aberration or blur.
Yes, the improvement I have experienced is "vast". My distance vision is stunningly good. And, because the old lens with all its defects has been replaced, the glasses I wear now give me exceptionally clear and easy vision when reading.
all the best for your wife's op
Dan