The orbicularis oculi is a circular muscle surrounding the eye. It plays a crucial role in closing the eyelids, allowing for blinking and protecting the eyes from irritants. This muscle is essential for maintaining eye moisture and overall eye health. Additionally, the orbicularis oculi is involved in facial expressions, such as squinting or winking. It is divided into two parts: the palpebral part, which gently closes the eyelids, and the orbital part, which tightly closes the eyelids. Proper function of this muscle is important for both vision and communication.