What muscle is responsible for closing the eyelid?

The muscle responsible for closing the eyelid is the orbicularis oculi.

Orbicularis oculi is a ring-shaped facial muscle that surrounds the eye socket. Its palpebral portion closes the eyelids gently during blinking and sleep, while its orbital portion contracts more forcefully when a person squeezes the eyes shut. A smaller lacrimal portion also helps move tears into the drainage system near the inner corner of the eye.

The muscle is controlled by branches of the facial nerve, cranial nerve VII. This is why facial-nerve problems, such as Bell’s palsy, can make it difficult to blink or fully close one eye. Incomplete closure can leave the cornea exposed and may require protection with lubricating drops or other treatment.

A frequent mix-up involves the levator palpebrae superioris, which performs the opposite major action: it raises the upper eyelid. The frontalis lifts the eyebrows, while the corrugator supercilii draws the eyebrows inward and downward. Orbicularis oculi is therefore the key muscle for both ordinary blinking and deliberate eye closure.