Binary tellurite glass systems of the forms TeO2(100−x)-xAn Om whereAn Om = La2O3 or V2O5 and x = 5 to 20 for La2O3 and 10 to50 for V2O5 were prepared. UV-spectra of these glasses were recorded in the range of200–700 nm at room temperature. The optical energy gaps E optical and $E_{\rmtail}$ have been calculated from the optical absorption edge. UV cut-off and IR cut-off havebeen measured. Calculations of the oxide ion average polarizability ( $\alpha_0^{2-}$ ) andoptical basicity (Λ) have been done.