Angular dependence of shielding effect of radiation protective eyewear for radiation protection of crystalline lens

Radiation protective (RP) eyewear effectively protects crystalline lenses from radiation exposure. A drawback of RP eyewear is the angular dependence of the shielding effect, which results from the design of the eyewear. In this study, 21 models of RP eyewear with different designs and lead equivalences were assessed. Each piece of RP eyewear was hung on a Styrofoam phantom that imitated the head, and a 0.125-cc ionization chamber dosimeter was placed at the position of the crystalline lens. The differences in angular dependence of the shielding effect were evaluated by changing the irradiation angle, and parameters that improved the angular dependence of the shielding effect—sufficient lead equivalence, large coverage design, and minimum gap between the crystalline lens and the RP eyewear—were identified. Thus, the findings highlight the importance of selecting RP eyewear according to the angular distribution and the nature of radiation exposure in the workplace for radiation workers.