An inversion of all or part of the lid margins that may be initiated by severe blepharospasm due to ocular or periocular pain. In many canine breeds it is an inherited disease. Inversion of the cilia or facial hairs creates further discomfort, conjunctival and corneal irritation, and if protracted causes corneal scarring, pigmentation, and perhaps ulceration. Early spastic entropion may be reversed if the inciting cause is removed, or further pain alleviated by everting the lid hairs away from the eye with mattress sutures in the lid, injections, eg, of procaine penicillin, into the lid adjacent to the entropion, or by palpebral nerve blocks. Established entropion may require surgical correction.