<p>Due to the distinctive optical, structural and chemical properties of glasses containing different constituents, they are promising materials in the ionizing radiation-shielding field and encapsulation of radioactive wastes. Here, a glass system La₂O₃–B₂O₃–Na₂O–Fe₂O₃ was prepared by the melt-quench method and investigated through the radiation-shielding competencies utilizing Phy-X software and spectroscopic properties. The optical basicity changed from 0.577 to 0.636 by about 10% with excessive La₂O₃ additions from 0 to 8&#xa0;mol%. The values of electronic polarizability changed from 1.528 to 1.615 by about 6% with further La₂O₃ concentrations from 0 to 8&#xa0;mol%. The electronegativity decreased from 2.650 to 2.529 with further La₂O₃ content. The increased behavior of both electronic polarizability and basicity refers to an increment in the ionic nature of the glass matrix. Further analysis of the ligand field parameters revealed declining values of the ligand field splitting parameter and increasing values of the Racah parameter with further La₂O₃ contents. This decrease in ligand field splitting parameter demonstrates the decreased interactions between Fe³⁺ cations and their ligands inside the glass matrix. Furthermore, the increased Racah parameter reflects that further covalency of Fe³⁺-ligand bonds decreases. Radiation-shielding studies demonstrated that increasing La₂O₃ contents from 0 to 8&#xa0;mol% enhanced the shielding efficiency, evidenced by an increase in linear and mass attenuation coefficients, and a decrease in the half-value layer. The radiation protection efficacy also increased with La₂O₃ contents from 0 to 8&#xa0;mol%. Finally, the best candidate for gamma radiation shielding is the sample that contains the highest La₂O₃ concentration in the present glass matrix.</p>