Hi. This sounds very similar to my girls eye. She did have good days sometimes even weeks! However, I spent too much time using a vet that never did appropriate tests such as schirmer or fluorescein stain. I didn;t know about them until I came here. She was being treated for a simple infection, and soon there were no more good days.
I found an excellent vet who immediatly sent Maddie to the ophthalmologist at Univ. of TN. We found out Maddie produces no tears in her left eye. This may be caused by a genetic defect-poorly developed tear duct- or permanent damage done by it being untreated in time- or others causes.
I hate not knowing. (This is the problem that brought me to YT.)
She has been on numerous tear stimulating medications and nothing worked. This is something we will have to deal with for the rest of her life, she will be 3 in May. I clean her eye out at least 6-7 times a day and keep it lubricated with drops just as many times. It is horrible because I know it can be painful for her at times.
Our only option is possibly a surgery that would reroute her salavia glad to her tear duct: parotid duct transposition. We are considering having this done this summer.
I would suggest you contact your vet and ask to be referred to an ophthalmologist.
Eyes are certainly not something to mess around with and once damage is done it may not be reversable.
I will say a prayer for your little guy and hopefully he will find a treatment that works. Keep us updated.