A system of power transmission to a contact lens comprises a contact lens 10 with an induction coil 13 and a magnetic component 20. The contact lens comprises at least a physiological signal sensing component 12, an induction coil, and an energy storage component. When the magnetic component 20 has a motion relative to the induction coil (for example, the magnetic component may be attached to the eyelid and produce this motion when the user blinks), an induced voltage is produced in the induction coil due to the electromotive force generated. The physiological sensing component may be used to measure intraocular pressure, humidity, temperature, pH or the composition of tears in the eye. The contact lens may comprise an energy storage component such as a battery or capacitor.
