I have had cataract surgery and now my eye is red?

I have had cataract surgery as well as retinal detachment surgery about half a year ago, and been on Predforte eye drops since then. I met my eye specialist 3 weeks ago and she said I should continue to use eye drops for 2 weeks because there is a slight infection. After 1 week of no drops my eye is still red?? Why??

Age: 37
medications: predforte