That is excellent that you have noticed that something is not right. It really helps when people pay attention to changes in their pet so that we can address problems early in the onset. As far as eye problems. …. Well, pugs are definitely one of the breeds that we see a lot of problems with the eyes- primarily because of their anatomy (bulging eyes). So they are more prone to ulcers, infections and other problems. With these breeds (and other breeds that have the same issues with bulging eyes) you want to always watch for changes. From what you describe, it could be something that is “not a problem” or possibly something more such as a conjuctivitis or even an ulceration. Allergies that affect the eyes are not that common in dogs. I would recommend having him checked out rather than taking a “wait and see” position. For this breed of dog you always want to have an eye problem checked out early on, just because they have such an incidence of eye problems turning into something serious. I hope this helps.