The glasses with the composition (15-x) Na2O–45B2O3–20Bi2O3–20SiO2–xLa2O3, where, x= (0≤x≥ 15) were successfully manufactured with a fast melt-quenching method. The density (ρ) of the glasses ranged from 4.913 to 6.497 g/cm3 and the molar volume (Vm) ranged from 29.68 to 28.54 cm3/mol. FTIR spectroscopy to achieve further understanding of the structure of the synthesized glasses was performed. FT-IR spectra confirmed that the addition of La2O3 modifies the glasses and broadens the absorption bands. The indirect and direct energy gaps increased as the amount of La2O3 in the sample increased, according to UV–visible spectroscopic data. It was discovered that the refractive index ranged from 2.249 to 2.275. The study employed the DTA to explore the thermal features of synthesized glasses. The study employed the Phy-X/PSD code to explore the radiation-shielding properties of these samples. At low (E) of 0.015 MeV, the values of MAC were found to be 67.624, 67.739, 67.845, 68.032, and 68.193 cm2/g, while at (E) (15 MeV), which were 0.040, 0.041, 0.0413, 0.0418, and 0.042 cm2/g, in increasing order for the glasses BBSNLa-0, BBSNLa-2.5, BBSNLa-5, BBSNLa-10, and BBSNLa-15. Moreover, the values of μm at (E) (15 MeV), which were 0.040, 0.041, 0.0413, 0.0418, and 0.042 cm2/g, for BBSNLa-0, BBSNLa-2.5, BBSNLa-5, BBSNLa-10, and BBSNLa-15 respectively. The combination of superior γ-radiation protection and favorable optical properties makes the BBSNLa-15 glass sample a promising candidate for applications in both optoelectronics and radiation protection. •The (15-x) Na2O–45B2O3–20Bi2O3–20SiO2–xLa2O3, glasses were prepared.•Density increased from 4.913 to 6.497 g/cm3.•The glass thermal stability increased.•The BBSNLa-15 sample a promising candidate for applications in both optoelectronics and radiation protecting.