Thank you for your reply to my question. I did have a retina tear about 20 years ago, but I can't really say the diplopia first appeared right after that. What I am concerned about now is will I get diplopia in my left eye after the catarac is removed in about a week. If that occurs I will not have good vision in either eye. I will be optomistic about the outcome. I can't leave it as it is now because the imbalance between the vision in my two eyes is too great. I can not get lenses to compensate for so much difference.
This is hard to answer without examining you. Monocular diplopia (double vision in 1 eye) can result from a number of things, like a corneal scar, uncorrected refractive error (nearsighted, farsighted, astigmatism), decentered implant lens, hazy posterior capsule behind the implant. Your surgeon will know if any of these is a factor. If there is a high degree of uncorrected refractive error, then an implant exchange might be needed. Since this involves another surgery, there are risks of infection, bleeding, tearing of the posterior capsule with need for vitrectomy, etc. Obtain a second opinion if needed.