Orbicularis Oculi
Head & Face
A genuine smile — called a Duchenne smile — uses this muscle. That's how you tell a real smile from a fake one.
Function
Closes eyelids, aids tear drainage
Origin
Medial orbital margin, medial palpebral ligament, lacrimal bone
Insertion
Skin around orbit, lateral palpebral raphe
Innervation
Temporal and zygomatic branches of facial nerve (CN VII)