Eye Muscle Anatomy: Understanding Blinking and Squinting

Blinking

* Primary muscles involved:

* Orbicularis oculi muscle (both palpebral and orbital parts)

* Corrugator supercilii muscle

* Secondary muscles involved:

* Frontalis muscle

* Procerus muscle

* Pyramidalis nasi muscle

Squinting

* Primary muscles involved:

* Orbicularis oculi muscle (both palpebral and orbital parts)

* Corrugator supercilii muscle

* Procerus muscle

* Secondary muscles involved:

* Frontalis muscle

* Pyramidalis nasi muscle

Blinking is a rapid, involuntary movement of the eyelids that helps to keep the eyes moist and free of debris. Squinting is a voluntary movement of the eyelids that is used to reduce the amount of light entering the eyes.