What is entropion? Entropion, or inward rolling of the eyelids, is a common abnormality of the eyelids in many species, especially dogs. It can affect one to all four of the eyelids, but in most cases, both eyes are affected. The inward rolling of the eyelids causes the hair around the eye to rub on the cornea, which causes constant discomfort and may lead to painful corneal ulcers. Additionally, chronic corneal irritation can lead to corneal scarring which can affect visio