There are many many women who decline the eye ointment both for vaginal and c-section births. I don't see any reason why you should get it other than the fact that most people don't do their homework and just follow the herd.
Although certain bacterias that can cause issues can be found in the eyes of c-section babies as well, there are some questions as to whether or not the antibiotic even actually prevents against these.
Your risk is low, as you know your history and have no STD's, I don't know why you'd choose to do it. I think it is recommended because there are so many women whose prenatal care is poor and it is an easy way to (maybe) prevent certain infections.
It will also blur baby's vision which can affect bonding with baby.
Here is a good idea if you decline the eye antibiotic: Watch for symptoms of infection, and treat if they develop. The most common symptoms are: lots of mucous discharge from the eyes, and swelling and redness of the eyelids. Newborns may also develop minor eye infections from contact with siblings or others. These are not related to sexually transmitted infections and are easily treated.
We didn't do it the second time around. Just signed the informed consent waiver.
Good luck!