Abstract: For the early detection of blindness-causing diabetic retinopathy, an apparatus for measuring the autofluorescence of the cornea of an eye, comprising means for tangentially illuminating the cornea, means for receiving the autofluorescent radiation generated in the cornea by this illumination, and means for processing the measured autofluorescent radiation, wherein the means for tangentially illuminating the cornea comprises at least one light source which radiates blue light and at least one filter which transmits at least a part of the blue light in a light path to the cornea, and the means for receiving the autofluorescent radiation generated in the cornea comprises at least one filter which transmits green light.

Abstract: An improved surface characteristic measurement system for measuring a characteristic of a surface comprising a processor, a light source for providing a light beam on the surface to be measured, a position sensing device for sensing a position of a diffused light diffused by the surface, and a photodiode for sensing intensity of a reflected light reflected by the surface. The position sensing device, which may be a PIN diode, provides a position signal to the processor indicative of position of the diffused light while the photodiode provides a reflected light intensity signal to the processor indicative of reflected light intensity. The processor determines the surface characteristic based at least one of the position signal and the reflected light intensity signal.