Gravitational lensing using ground-based optical telescopes has yielded
some of most exciting results in the field of exoplanet searches, such as
the discovery of the first "Earth-like" exoplanet, the first statistics of
mass distribution of planets in the Milky Way, the detections of
free-floating planets, and the precise mass measurement of an exoplanet.
When used on cosmological scales in a Multiwavelength observing strategy,
the physics of Active Galactic Nuclei and fundamental physics questions
like testing of gravitational lensing achromaticity can be studied.

An introduction about strong gravitational lensing and microlensing will
be given in the talk, together with the highlight results obtained by the
PLANET (Probing Lensing Anomalies NETwork) telescope network in exoplanet
searches, as well as gravitationally lensed quasar studies with the MAGIC
telescopes.