In Greek mythology, what did Perseus use to view Medusa safely without meeting her gaze?

Perseus used a polished shield to view Medusa safely without meeting her gaze.

Medusa’s direct gaze was believed to turn living beings to stone. To avoid looking straight at her, Perseus used the reflective surface of a shield, traditionally associated with Athena, to locate and approach the sleeping Gorgon.

The reflection allowed Perseus to guide his sword while looking away from Medusa herself. This detail is one of the most recognizable parts of the myth and explains how a mortal hero could defeat a monster whose gaze was fatal.

The object is usually described as a polished shield rather than a mirror. Later paintings and retellings sometimes emphasize the reflective metal, but the shield remains the canonical item in the myth.