There is a difference between quantity of vision and quality of
vision. Quantity can be measured in diopters (-1.50) or Snellen
(20/whatever). Quality is more likely measured with contrast
sensitivity or wavefront aberrometer analysis. Two people with the
same quantity can have very different quality and the other way
around.
Considering that if all went well with your cataract surgery and you
have a good IOL, the quality of your vision is probably pretty good.
I think the difference between you and your friend is the tolerance
for driving with poor vision. Rather than obsessing about your
vision, I'd obsess about not being on the road when your friend is
driving. 8^)
Glenn Hagele
Executive Director
Council for Refractive Surgery Quality Assurance
Email to glenn dot hagele at usaeyes dot org
http://www.USAEyes.org
http://www.ComplicatedEyes.org
I am not a doctor.