US Patent 10394057 Eyes closed interface

An eye-mountable device including a lens including a polymeric material, the lens operable to be removably mounted over a corneal surface of an eye and to be compatible with a motion of an eyelid when the concave surface is so mounted; a sensor coupled to the lens and operable to provide output data indicative of whether an eyelid of an eye on which the lens is mounted is closed; and a display operable to display a light signal in response to the output data from the sensor that the eyelid is closed. A method including determining whether an eyelid of a wearer of an eye-mountable device is closed; and when an eyelid of a wearer is closed, sending a light signal from the eye-mountable device.