Disclosed is a flexible insert (100) for placement on the human eye, comprising a light source (110) in said insert such that light emitted from the light source is shielded from the human eye upon correct placement of the insert on the human eye, a light-responsive material (120) placed in the light path of the light source, said light-responsive material emitting light upon stimulation by the light from said light source, the intensity of said stimulated emission being sensitive to a chemical interaction of the light-sensitive material with an analyte of interest, a photodetector (130) for detecting the light emitted by the light-responsive material； and a transmitter (140) coupled to the photodetector for transmitting a photodetector reading. The insert may be used in conjunction with a reader for automated monitoring of an analyte of interest such as glucose in the tear fluid of its wearer.
