I've posted on bug-eyed dogs in the past, and you may recall (or it may be intuitively obvious to you) that they are more susceptible to eye injuries than a dog whose eye is nice and protected back inside the socket (instead of bulging out of it). This is a rather extreme example. We did a little work on him to give him a less extreme conformation.
This is a generic Boston Terrier that I googled up for you. Still buggy-eyed, but not nearly so extreme. Still more susceptible to eye injuries than the average dog. Today we looked at a Boston Terrier dog who had been holding his left eye shut for THREE WEEKS. "He just started to open it again yesterday." I couldn't help myself. I said, "Three weeks, huh? What's your hurry, lady?" This wasn't a good thing to say, as it could make the owner feel dumb, or feel bad. Then where will you be on getting cooperation? Nowhere, that's where. But, as I said, I couldn't help myself.
It turns out that three or four months ago, he had his eye shut for two weeks and then "it got okay". So, they figured two weeks was probably an acceptable, kind of normal phenomenon. But when it went to three weeks, well...
You need to understand: these are nice people and they love their dog and they are not stupid. For some reason, something just didn't "click" here. When things sunk in a little, they were very distressed and anxious to fix it.
I think of my own eye and how uncomfortable I am when anything gets wrong for even a second: an eyelash, a speck of dust, anything. This dog had a superfical corneal ulcer. He had apparently been suffering with this for three weeks. "Hokey smokes, Bullwinkle!"
Fortunately, the ulcer remained superficial. With a bug-eyed dog with poor tear film coverage, and reduced ability to fully blink his eye, the ulcer could easily have gone deep and perforated his cornea. As it is, with very conservative treatment, I expect him to be fully healed (and a lot more comfortable) in just a few days.
I couldn't tell you how many times someone has come in with a squinting, red eye that has had a fox-tail weed awn in it for a week or more. "I been putting Visine in it."
Man, if there is something wrong with that eye, let's get it looked at pronto. Your eye is sensitive, and so is your pet's eye.