  Physical geometry and optical properties of objects are correlated: cylinders
focus light to a line, spheres to a point, and arbitrarily shaped objects
introduce optical aberrations. Multi-functional components with decoupled
geometrical form and optical function are needed when specific optical
functionalities must be provided while the shapes are dictated by other
considerations like ergonomics, aerodynamics, or esthetics. Here we demonstrate
an approach for decoupling optical properties of objects from their physical
shape using thin and flexible dielectric metasurfaces which conform to objects'
surface and change their optical properties. The conformal metasurfaces are
composed of silicon nano-posts embedded in a polymer substrate that locally
modify near-infrared ($\it{\lambda}$ = 915 nm) optical wavefronts. As proof of
concept, we show that cylindrical lenses covered with metasurfaces can be
transformed to function as aspherical lenses focusing light to a point. The
conformal metasurface concept is highly versatile for developing arbitrarily
shaped multi-functional optical devices.
