Until now, the radiation protection community had assumed that only high doses of 2 Gy or more cause cataracts. However, new data from the atomic-bomb (A-bomb) survivors suggest that the dose threshold for both minor opacities and vision limiting cataracts may be below 1 Gy. Other studies have shown similar results in recent years. In 2011, the International Commission on Radiological Protection (ICRP) revised their guidelines for permissible occupational and medical exposures to the eye.