An eye-implantable electrowetting lens can be operated to control an overall optical power of an eye in which the device is implanted. A lens chamber of the electrowetting lens contains first and second fluids that are immiscible with each other and have different refractive indexes. By applying a voltage to electrodes of the lens, the optical power of the lens can be controlled by affecting the geometry of the interface between the fluids. To prevent fouling the surface due to folding or other manipulation of the lens during the insertion process, one or more surfaces within the lens chamber is highly underwater oleophobic.