A lens comprises an internal cavity structure formed by dissolution of a soluble insert material. The internal soluble material may dissolve through a body of a lens such as a contact lens in order to form the cavity within the contact lens. The cavity within the lens can be shaped in many ways, and corresponds to the shape of the dissolved material, such that many internal cavity shapes can be readily fabricated within the contact lens. The insert can be placed in a mold with a pre-polymer material, and the pre-polymer material cured with the insert placed in the mold to form the lens body. The polymerized polymer may comprise a low expansion polymer in order to inhibit expansion of the lens when hydrated. The polymer may comprise a hydrogel when hydrated. The soft contact lens material comprises a sufficient amount of cross-linking to provide structure to the lens and shape the cavity.