A light scattering study has been performed on two efficient Raman scattering optical glasses from 0.15 to 3 THz at low temperatures. In the low-frequency range, we found an increase of the scattered intensity below 10 K. In contrast to previous investigations, mainly in vitreous silica, which have found an absence of light scattering by resonant interaction with two-level systems in glasses, our results are in good agreement with theoretical predictions which assume a coupling of light with tunneling states. [S0031-9007(96)00687-4]