[en] The amplitude of process yy → ππ and pion polarizability within the linear sigma-model are considered. Calculations in the current algebra and in the field theory with Lagrangians have led to various theoretical predictions as to the πsup(0)-meson polarizability. It is shown that yy → ππ amplitude has 'anomalous' behaviour from the point of view of the current algebra hypothesis and changes sharply near the threshold of two-pion production. In this connection the experimental study should give different values for pion polarizability depending on an energy region measured