My Husband Ed Was Given Eye Drops, Neomycin/Polymyx/Dex Oph Susp

My husband Ed was given eye drops, Neomycin/Polymyx/Dex Oph Susp for inflammation in one eye. He took the drops for the recommended 10 days, went back to his pOpthomologist with other symptoms including itching and inflammation. She told him to get some eye drops without preservative. He has not improved, having crusty, itchy eye and redness and swelling under the eye and hurts a lot. Please advise, as I think he might have allergic conjunctivitis, thank you. Norma Decker. YYYY@YYYY