US Patent 7864440 Optical lens with variable focal length

The invention concerns an optical lens comprising a cavity formed by two transparent windows and a peripheral frame positioned in between, said cavity containing first and second liquids, non miscible, forming an interface, said interface being movable by electrowetting on a wall of said peripheral frame by application of a voltage between first and second electrodes, wherein said wall has a non symmetrical revolution surface, the geometrical shape of which is calculated such that said interface is of a predetermined shape, for example substantially spherical, for at least one value of said voltage.