A variable geometry contact lens structure having a thickness t sufficient to carry an active payload is constructed using layers of materials with high oxygen transmissibility and low oxygen transmissibility. The low transmissibility layer provide mechanical support for the active payload, and the high transmissibility layers provide adequate oxygen transmission to the cornea of the user's eye. The ratio of the thicknesses of the two layers changes abruptly at the boundaries between the payload and non-payload regions of the structure. For example, at a boundary of the payload region, a ratio of thicknesses of the high transmissibility layer t1 to thickness of the low transmissibility layer t2, R=t1/t2, changes by at least 2:1 over a lateral distance of not more than t.
