An apparatus for measuring intraocular pressure (IOP) comprises a contact lens including an inner surface contoured to a surface portion of an eye and a sensor disposed in the contact lens. The sensor comprises a contact surface for making contact with the surface portion of the eye. The contact surface includes an outer non-compliant region and an inner compliant region fabricated as an impedance element that varies in impedance as the inner compliant region changes shape. The sensor further comprises a region of conductive material electrically coupled to the impedance element of the compliant region and responsive to an external signal for energizing the impedance element so that the IOP may be determined.