The method enables a non-homogeneous diffusing object to be examined by illuminating the object with a continuous light by means of a light source. It previously comprises reconstruction of the three-dimensional spatial mapping of an attenuation variable representative of the diffusion and absorption non-homogeneities of the object, by resolving a diffusion equation ∇2F({right arrow over (r)}S, {right arrow over (r)})−k′2({right arrow over (r)})F({right arrow over (r)}S, {right arrow over (r)})=ASδ({right arrow over (r)}−{right arrow over (r)}S). In the diffusion equation, AS is a constant, {right arrow over (r)} the spatial coordinate of any point of the mesh of a volume at least partially containing the object, and {right arrow over (r)}S the spatial coordinate of the light source. The transfer functions of an equation used for reconstructing the distribution of fluorophores integrate the attenuation variable reconstituted in this way.