Cherry Eye is the name given to the tear gland wrapped around the cartilage of the third eyelid that prolapses (bulges or pops out from beneath the eyelid). It looks like a small cherry in the inside corner of the eye.
One cause of the prolapse is believed to be a weakness of the connective tissue around the gland and that this may be a congenital defect. Other causes may be different types of infection, trauma, cancer, compromised immune system.
Cherry Eye can occur with any breed, but is most common in dogs with pushed-in faces.
Treatment was removal of the third eyelid, but this proved to interfere with tear production and resulted in dry eye syndrome. If the gland must be removed, your dog may require artificial tears for the rest of his life. However most surgeries can usually reposition the third eyelid and the gland, correcting the problem and maintaining tear production.
Any eye problem should be promptly seen by your veterinarian as it can lead to further complications.