Dogs have three eyelids: two that are visible and a third one that is usually hidden from view in the inner corner of the eye. The third eyelid contains a tear-producing gland. This gland is also usually invisible, but some dogs have a congenital weakness of the ligaments that hold it in place.When these ligaments fail, the gland pops out of its normal location, and it looks like there is a “cherry” stuck at the inner corner of the eye.To treat cherry eye, the animal eye surgeon will perform a straightforward surgical procedure that will help return the gland to its normal position.