With vision problems
You should have your cataracts operated on cataracts when they affect your activitities of daily living.
"you have problems doing things you like, or need to do", or there is medical reasons that the cataracts should be taken care of (causing glaucoma
!). There is no set vision
(i.e. 20/40 or 20/50) that indicates you should have surgery. You should have symptoms, or need to pass drivers exam.