Orbicularis oculi

Muscle responsible for closing the eyelids and surrounding the eye.

The orbicularis oculi is a circular muscle located around the eye. It consists of three parts: the orbital portion, which encircles the eye; the palpebral portion, found in the eyelids; and the lacrimal portion, associated with the tear duct. This muscle plays a critical role in protecting the eye and facilitating blinking.

Terminologia Anatomica

orbicularis-oculi

System

Muscular system

Function

The primary function of the orbicularis oculi is to control the movements of the eyelids. By contracting, it allows for the closing of the eyelids, which is essential for various reasons: blinking helps to spread tear film across the surface of the eye to keep it lubricated, protects the eye from debris and bright lights, and plays a significant role in expressing emotions. Additionally, the muscle works to drain tears from the eye into the nasolacrimal duct, ensuring that excess fluids do not interfere with vision. Overall, the orbicularis oculi is crucial for maintaining ocular health and protecting the delicate structures of the eye.

Location

The orbicularis oculi is situated in the facial region, originating from the frontal bone and the maxilla before encircling the eye. The muscle lies subcutaneously and is positioned around the bony orbit of the eye, extending horizontally and vertically across the eyelids. The palpebral part inserts into the eyelids themselves, while the orbital portion covers a larger area and contributes to dynamic facial expressions. Its strategic location allows for immediate and efficient eye protection and showcases its vital role in facial movement.

Did You Know?

The orbicularis oculi is not only important for blinking but also aids in facial expressions such as winking or squinting.
This muscle is incredibly versatile and can contract with varying intensity, allowing for gentle blinking or forceful closing of the eyes.
When laughing or expressing joy, the orbicularis oculi helps create the characteristic 'crow's feet' wrinkles at the corners of the eyes.