Borosilicate glasses within 25B2O3–15Si2O–10CaO-(50-x)BaO-xTa2O5 system at different Ta2O5 contents (x = 0, 4, 8, 12, and 15 wt%) were synthesized via quenching technique. The effect of irradiation doses of both 10, and 40 kGy, as well as the Ta2O5 ratio on the structural and optical characteristics of the prepared glasses were studied. The investigations were carried out using UV–Vis–NIR spectrophotometer, differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) techniques. Physical parameters such as density, molar volumes, refractive index, optical bandgap, Urbach energy, optical density, extinction coefficient, optical sheet resistance, and thermal emissivity of 25B2O3–15Si2O–10CaO-(50-x)BaO-xTa2O5 samples with different irradiation doses were investigated. The results show that irradiation does not affect the crystal structure for the present samples even at 40 kGy. The optical aspects reveal the indirect allowed optical transition for the studied samples. The evaluated optical parameters show an effective influence towards both Ta2O5 content and irradiation does which forces the optical applications.