I was prescribed polymyxin-B/Trimethoprim ophthalmic solution for conjunctivitis. My symptoms cleared quickly; however, I began to experience increased redness in my eyelid and eye along with tearing and light sensitivity. My Rx has been changed to tobramycin. These 2 formulas have the same inactive ingredients. So, am I likely to experience the same adverse effects, or are the effects due to the active ingredients?