The theoretical analysis of structures of the bound and resonance states in 8 Li and 8 B nuclei is performed within a three-cluster microscopic model. In the framework of this model, 8 Li and 8 B nuclei are considered as three-cluster configurations 4 + 3 + and 4 + 3 + , respectively. A distinguished peculiarity of the model is that it allows us to consider the polarizability of weakly bound nuclei such as 7 Li composed of an alpha particle and a triton or 7 Be composed of an alpha particle and 3 He. Gaussian and oscillator bases are used to expand the three-cluster wave function and to represent the many-channel Schrödinger equation in a matrix form. The main attention of the present study is paid to the effects of cluster polarization on the spectrum of bound and resonance states of 8 Li and 8 B and on the elastic and inelastic + 7 and + 7 scattering. It is shown that the cluster polarization has a great impact on parameters of the bound and resonance states in 8 Li and 8 B. For instance, it decreases the energy of resonance states by 0.7-2.0 MeV and increases their lifetime by more than three times. The roles of spin-orbital and Coulomb interactions in the formation of the spectrum of excited states in nuclei 8 Li and 8 B are studied in detail. In particular, it is found out that the Coulomb forces shift up the energy of resonance states in 8 B with respect to the position of corresponding resonance states in 8 Li and increases their widths.