Patent ID: 7342725

Claim:
An optical element ( 200 ; 300 ) for providing a variable refractive surface, the element comprising: a chamber ( 215 ) defined by at least one side wall ( 270 ); an optical axis ( 90 ) extending through the chamber ( 215 ); the chamber ( 215 ) containing a first fluid ( 220 ) and a second fluid ( 230 ) in contact over a meniscus ( 225 ) extending transverse the optical axis ( 90 ), the perimeter of the meniscus being constrained by said side wall ( 270 ), the fluids ( 220 , 230 ) being substantially immiscible and having different indices of refraction; a first electrowetting electrode ( 242 ; 243 ) arranged to act on at least a portion of the meniscus perimeter constrained by said wall ( 270 ); and a second electrowetting electrode ( 280 ) extending through the meniscus ( 225 ).