Method and apparatus for determining an autofluorescence value of skin tissue

A method for determining an autofluorescence value of skin tissue of a subject, comprising the steps of : - irradiating material of said skin tissue with electromagnetic excitation radiation of at least one wavelength and/or in at least one range of wavelengths; - measuring an amount of electromagnetic, fluorescent radiation emitted by said material in response to said irradiation; and - generating, based upon said measured amount of fluorescent radiation, a measured autofluorescence value for the concerning subject.; The determined autofluorescence value is obtained by correcting the measured autofluorescence value for characteristics of a reflected part of an excitation spectrum and/or an emission spectrum from said material in response to such irradiation and/or for characteristics of reflectance measurements at wavelengths other than said at least one wavelength and/or other than in said at least one range of wavelengths, in such manner that the dependency of the determined autofluorescence value upon dif