Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
A contact lens device can include a sensor for measuring an analyte, such as glucose, in a tear film. The sensor can be an electrochemical sensor that includes a working electrode and a counter and/or reference electrode. An electrochemical reaction involving the analyte can transfer electrons to or from the working electrode so as to generate a current related to the concentration of the analyte. In some instances, a reagent can be located proximate to the working electrode to facilitate a selective, electrochemical reaction with the analyte.
A contact lens device can also communicate sensor readings to an external reader. For example, the contact lens can include an antenna that is configured to receive radio frequency radiation from the external reader and produce a backscatter signal based on a sensor reading.