The antenna is one of the key building blocks of many wearable electronic device, and its functions include wireless communications, energy harvesting and radiative wireless power transfer (WPT). In an effort to realise lightweight, autonomous and battery-less wearable devices, we demonstrate a reconfigurable antenna design for 5G wearable applications that require ultra-low driving voltages ($0.4$-$0.6\,$V) and operate over a high frequency range ($3.3$-$3.8\,$GHz). For smart glasses application, previous antenna designs were `fixed' and mounted on the eyeglass frame itself. Here, we demonstrate a reconfigurable design that could be achieved on the lens itself, using an anisotropic liquid crystal (LC) material. We demonstrate how LC alignment and electric field patterns strongly influence the tuning capabilities of these antennas in the gigahertz range and present a smart, reconfigurable spiral antenna system with a LC substrate.