According to NCRP, what is the annual limit for radiation exposure to the lens of the eye for radiologic technologists?

• A. 5 mSv annually
• B. 50 mSv annually
• C. 150 mSv annually
• D. 500 mSv annually

Answer: (C)

The lens of the eye is highly radiosensitive, so protecting it from radiation exposure is essential. To limit the risk of radiation-induced cataracts in workers, NCRP set an annual dose limit specifically for the lens. The traditional occupational limit for the lens is 150 millisieverts per year. This value reflects a balance between allowing necessary diagnostic work and keeping eye dose low enough to minimize long-term eye effects, using shielding, appropriate distance, and monitoring to stay within the limit. Note that newer guidelines have lowered recommended lens limits (to about 20 mSv per year averaged over five years), but the NCRP standard cited here historically remains 150 mSv per year.