An optical element (1) for correcting refractive index related aberrations comprises a fluid chamber (5) which is provided with an electrode configuration (2,12) and includes a first, electrically conducting, fluid (B) and a second, non-conducting, fluid (A), and an interface (14) between the fluids, the fluids having different Abbe numbers. By applying a voltage (VO to the electrode configuration electrowetting forces are generated, which deform the shape of the interface (14,14′) and determine the corrective power.