The present invention relates to a method of disinfecting a region, in particular a skin region of a patient, wherein the method comprises the following steps: a) Application of an optically effective substance to the region； and b) Application of a disinfectant to the region, wherein the optically effective substance and the disinfectant are configured such that the optically effective substance is removed by the disinfectant or its optical properties are changed by the disinfectant.
