Abstract: A unique glucose sensor to determine the glucose level in patients, for example, for use in treating or diagnosing diabetes. The patient's eye is automatically scanned using a dual source of polarized radiation, each transmitting at a different wavelength at one side of the cornea of the patient. A sensor located at the other side of the cornea detects the optical rotation of the radiation that passed through the cornea. The level of glucose in the bloodstream of the patient is a function of the amount of the optical rotation of the radiation detected at the other side of the cornea of the patient. The result is transmitted to a remote receiver that is coupled to a readout device to thereby provide non-invasive glucose determinations of high specificity and reliability.