Usually you have one eye that is dominant so modest errors in the other one don't show. You will have a headache though if a lens falls out.
Both eyes is always marginally better than either one on its own but the dominant eye gets the lions share of attention on seeing fine detail. Binocular vision is handy for judging distances though.
Provided that you don't have much astigmatism then that should work.
But you really need to find a better optometrist! When mine does me I can read one line or two lines below what is normally considered 20:20 vision with the full correction applied in his test frames.
My distance vision is to that precise prescription and tack sharp. My close up are both the previous prescription and more than adequate.
I was slightly horrified to be told that my distance vision was still within the legal parameters where I could drive without glasses!