Protopsis is an emergency medical condition in which an otherwise healthy eye explodes or falls out of the orbital socket that normally contains it. Though it can happen in any breed, it seems to occur most often in those with short and wide faces such as pugs, bulldogs, and pekingnese.
Protopsis can happen for a wide variety of reasons. It could occur as the result of trauma such as a scratch or bite by another animal, even when the resulting damage is not externally visible. Likewise, it could occur as the result of pressure exerted upon the inner eye from the build-up of ocular fluids. It's even possible for protopsis to happen spontaneously with no discernible cause whatsoever. [...]