Tell your physician. Some but not all patients have "floppy iris syndrome" which increases the risk of surgery. If the surgeon knows about it then special techniques are used which can minimize the chance of this problem.
I need cataract sugery, but the opthamologist who examined me was very discouraging because I took Flomax briefly almost five years ago. The reason he was reluctant is that I have not usable vision in my right eye due to undiagnosed problems in childhood. Today the eye would have been patched in childhood, etc. and/or had surgery to make it useful. He said therefore, because of possible complications related to Flomax, Now, I would be risking my entire vision, not just vision in the one good eye!
Many years ago, I was told by another opthamologist that the right eye was actually physically perfect, and would "probably take over automatically" if something disastrous ever occurred to my left eye! Today's doctor said that unfortunately, that is not true. What am I to believe? There must be surgeons who have special training with Flomax and its problems with the iris!!
You are considering surgery on your "bad" eye, correct. Most likely that eye suffers from amblyopia from what you've been told. If for instance the best your bad eye has ever seen is 20/200 then the best you could expect from a perfect operation is 20/200. So you will need to rachet down your expectations that surgery will make it see normal.
Now having said that if you have a moderate or big cataract that is causing glare, loss of peripheral vision, "rivalry" with the good eye or the cataract is getting "hard" then there is no reason not to have surgery.
I wouls suggest you get a second even a third opinion from other eye surgeons. So many men are on flomax now that almost all surgeons have experience doring surgery for "floppy irises" These problems can be reduced with special strong dilating eye drops, iris hooks or dilation rings.
Find more eye MDs near you at www.aao.org
PS Its unlikey that if something horrible happened to your good eye and it was totally blind that your bad eye would recover normal vision, so take good care of the good eye