This book presents a new diagnostic approach that utilizes complex statistical, correlation, fractal, and singular analysis of spatial distribution of the Stokes vector of scattered polarized light in different diffraction zones. The technique is able to identify changes in the distribution of optical axes and the birefringent indices of multi-layered fibrillar networks of biological tissues. The book also presents various scenarios for the formation of polarization singularities in laser speckle images of phase-inhomogeneous, multi-layered biological tissues in terms of the characteristic values of Mueller-matrix images. Moreover, in the context of potential diagnostic applications, it discusses the states of polarization singularities and their changes associated with the pathological abnormalities of the extracellular matrix of human tissues, its spatial peculiarities and structural orientation.