Non-invasive and continuous glucose monitoring is of increasing significance since diabetes mellitus has been a global problem, not only the developed country. Usually, continuous glucose monitors (CGMs) use relationship between blood glucose and other body fluids. Particularly, we focused on the relationship between blood glucose and tear glucose. A soft-contact lens (SCL) biosensor has been developed for assessment of blood glucose by real-time tear sugar monitoring. The SCL biosensor has film electrodes on the rounded surface of polydimethyl siloxane (PDMS) contact-lens and glucose oxidase (GOD) was immobilized on the sensing region of the electrodes. In this paper, the status of SCL biosensor development and the application of the SCL biosensor in real-time monitoring of tear glucose are reviewed.