One of my bitches had an ulcer on the eye and was also cloudy , sometimes looked like clearing then would flare up again , nemerous trips to the vet and various creams nothing would take it away , anyway sent to an eye specialist knew what was wrong in minutes , due to an injury a muscle in the eye lid had been damaged and was rubbing on the eye.
Small operation and a bit of bill , bitch sorted and never any probs since . No amount of creams etc where ever going to heal her , sometimes its not as straight forward as it looks