1A very small (photographic, contact, etc.) lens.
A single discrete astronomical object (such as a star or planet) that acts as a gravitational lens. Compare "macrolens", microlens .
1960s; earliest use found in Stewart Duke-Elder (1898–1978), ophthalmic surgeon. From micro- + lens.
Of a single star, planet, etc.: to refract (electromagnetic radiation from an astronomical object, or the image of that object) by microlensing. Also without object.
1980s. From microlens.