The Procerus muscle is a small muscle located in the forehead between the eyebrows. It is a thin, triangular muscle that extends from the nasal bone to the forehead skin. It is responsible for drawing down the medial angle of the eyebrows and wrinkling the skin over the bridge of the nose.

The Procerus muscle is used in a variety of facial expressions, including frowning, scowling, and concentrating. It is also involved in conveying emotions such as worry, anger, and confusion through facial expressions. Although the Procerus muscle is small and relatively minor compared to other facial muscles, it plays an important role in facial expression and nonverbal communication. Its function is also critical in maintaining proper eye function by preventing glare and reducing eye strain.

Dysfunction of the procerus muscle can lead to various issues, including difficulty concentrating, difficulty seeing clearly, and visual discomfort. It can also lead to difficulty conveying certain emotions through facial expressions.