One vet described a dog who bumped into the edge of his kennel and popped out his eye.
"It happens completely all of a sudden," Krafchik said.
But there's no need to live in fear - oftentimes, if owners take action quickly, the eye can be reattached. In one study of dogs with proptosis, 27 percent of the affected dogs had their eye reinserted and their vision restored.
Even if the eye can't be saved, dogs still have a chance at a very happy life.
"I see tons of dogs with only one eye," Dr. Chaim Litwin, a veterinarian in Woodbridge, Connecticut, told The Dodo. "They generally do quite well."