Patent ID: 7126903

Claim:
A variable focus lens including a substantially cylindrical fluid chamber having a cylinder wall, the fluid chamber including a first fluid (A) and an axially displaced second fluid (B), the fluids being non-miscible, in contact over a meniscus ( 14 ) and having different indices of refraction, a fluid contact layer ( 10 ) arranged on the inside of the cylinder wall, a first electrode ( 2 ) separated from the first fluid and second fluid by the fluid contact layer, a second electrode ( 12 ) acting on the second fluid, the fluid contact layer having a wettability by the second fluid which varies under the application of a voltage between the first electrode and the second electrode, such that the shape of the meniscus varies in dependence on the said voltage, wherein the wettability of the fluid contact layer by the second fluid is substantially equal on both sides of the intersection of the meniscus with the contact layer when no voltage is applied between the first and second electrodes.