Domain structure of relaxor ferroelectrics was obtained theoretically by T-matrix method. First we discuss numerical aspects of T-matrix computations specific for spheroidal particles and present results of benchmark computations for a simple Chebyshev's particle model. Then we report results of extensive computations for polydisperse spheroid with a refractive index of PbMg1/3Nb2/3O3 (PMN), PLZT-ceramics and PbZn1/3Nb2/3O3 (PZN) and effective size parameters ranging from 1.0 to 10 with and without external electric field. These computations parallel to our previous study of light scattering by randomly oriented cylinder. The correlation between ferroic distortions of the PMN, PZN, and PUT under external electric field and the light scattering is discussed.