The present invention provides for a device for use in non-invasive inspection measurement and/or monitoring of a human or animal subject's eye, the device having a first optical system which comprises illumination means for selectively directing illumination light onto a selected structure of the eye for direct and diffuse reflectance there from and for providing the illumination light in one or more pulses, receiving means for receiving light returning from the eye as a result of illumination by the illumination light and arranged to record the returning light intermittently at a selected timing relative to the pulse(s) of illumination light so as to discriminate between directly or diffusely reflected light returning from the selected structure and other reflected light for analysis of the said directly or diffusely reflected light.