Entropion is caused by weakness of the lower lid retractor muscle, loss of contraction of the orbital septum and lower lid skin to hold the lid orbicularis muscle, and lack of adequate support behind the eyelid in older adults with reduced orbital fat. Scarring lid entropion can occur in both upper and lower lids. There is scarring of the lid conjunctiva and lid plate due to contraction. Pathology: Congenital entropion is most often seen in infants and children and is more common in females than males, mostly due to medial canthus, overdevelopment of the orbicularis muscle at the lid margin, or hypoplasia of the lid plate. Spastic entropion occurs mostly in the lower lid and is commonly seen in the elderly, also known as senile entropion. It is caused by weakness of the lower lid retractors, loss of contraction of the orbital septum and lower lid skin, and lack of adequate support behind the eyelid due to reduced orbital fat in the elderly. Scarring lid entropion can occur in both upper and lower lids. There is scarring of the lid conjunctiva and lid plate due to contraction. Examination: 1. The lid margin deviates from its normal position and curls significantly toward the eyeball, with the eyelashes subsequently inverted toward the heel, irritating the cornea and bulbar conjunctiva. 2. Due to long-term irritation, severe cases evolve into corneal ulcers, which also form corneal opacities after healing, leading to varying degrees of visual impairment and even blindness. The diagnosis is easily made based on the patient’s age, the presence or absence of trachoma, and the clinical presentation. 3. Congenital entropion is often bilateral, while spastic and scarring entropion can be unilateral. Patients have photophobia, tearing, tingling, and eyelid spasm. 4. Examination reveals curling of the lid, especially the lid margin, toward the eyeball. The corneal epithelium may be detached and fluorescein may be diffusely stained. If the infection is secondary, it may develop into a corneal ulcer. If left untreated for a long time, the cornea becomes neovascularized and loses its transparency, causing vision loss.