What is how does monocle stay on?

Monocles typically stay on the wearer's eye through a combination of pressure and muscle control. The monocle is held in place by the muscles of the wearer's eyebrow and cheek, which exert enough pressure to keep the lens in place. Additionally, the shape of the lens and the curvature of the wearer's eye work together to create a natural suction that helps keep the monocle in place. Some monocles may also have a small metal clip or spring that attaches to the wearer's clothing, providing additional stability. Overall, wearing a monocle requires practice and patience to ensure that it stays in place and provides clear vision.