A method for analyzing the skin of a patient, comprising the steps of: - placing an optical medium on a surface of the skin such that at least a portion of the surface of the optical medium is in contact with the surface of the skin; - emitting an excitation light beam having an excitation wavelength through the portion of the surface of the optical medium that is in contact with the surface of the skin onto the surface of the skin such that the excitation light beam is at least partially absorbed in the skin; - emitting a measurement light beam through the optical medium onto the portion of the surface of the optical medium that is in contact with the skin surface such that the measurement light beam and the excitation light beam overlap at an interface of the optical medium and the skin surface at which the measurement light beam is reflected, wherein an excitation light beam absorbed in the skin is capable of altering the optical path of the measurement light beam through the optical medium; - detecting a deflection of the reflected measurement light beam depending on the wavelength of the at least partially absorbed excitation light beam, wherein the degree of deflection correlates with the degree of absorption of the excitation light beam in the skin; and - analyzing the skin based on the detected deflection of the measurement light beam depending on the wavelength of the at least partially absorbed excitation light beam, wherein analyzing the skin comprises determining the blood glucose level of the patient, determining a water content of the skin of the patient, determining a protein composition of the skin of the patient, or determining a protein composition of the skin of the patient in different skin layers. - placing an optical medium on a surface of the skin such that at least a portion of the surface of the optical medium is in contact with the surface of the skin; - emitting an excitation light beam having an excitation wavelength through the portion of the surface of the optical medium that is in contact with the surface of the skin onto the surface of the skin such that the excitation light beam is at least partially absorbed in the skin; - emitting a measurement light beam through the optical medium onto the portion of the surface of the optical medium that is in contact with the skin surface such that the measurement light beam and the excitation light beam overlap at an interface of the optical medium and the skin surface at which the measurement light beam is reflected, wherein an excitation light beam absorbed in the skin is capable of altering the optical path of the measurement light beam through the optical medium; - detecting a deflection of the reflected measurement light beam depending on the wavelength of the at least partially absorbed excitation light beam, wherein the degree of deflection correlates with the degree of absorption of the excitation light beam in the skin; and - analyzing the skin based on the detected deflection of the measurement light beam depending on the wavelength of the at least partially absorbed excitation light beam, wherein analyzing the skin comprises determining the blood glucose level of the patient, determining a water content of the skin of the patient, determining a protein composition of the skin of the patient, or determining a protein composition of the skin of the patient in different skin layers.