With the International Commission on Radiological Protection's (ICRP) reduction in the radiation dose threshold for cataracts, evaluating and preventing radiation exposure to the lens of the eye among interventional radiology (IR) staff have become urgent tasks. In this study, we focused on differences in lens-equivalent dose (HT Lens) to which IR nurses in three hospitals were exposed and aimed to identify factors underlying these differences. According to analyses of time-, distance-, and shielding-related factors, the magnitude of the HT Lens dose to which IR nurses were exposed could be explained not by time or shielding but by the distance between the X-ray exposure field and the location of the IR nurse. This distance tended to be shorter in hospitals with fewer staff. The most effective means of reducing the exposure of the lenses of IR nurses' eyes to radiation is to position them at least two meters from the radiation source during angiography procedures. However, some hospitals must provide IR departments with comparatively few staff. In work environments where it is infeasible to reduce exposure by increasing distance, interventions to reduce time by managing working practices and investment in shielding equipment are also important. This study was not registered.