What is the annual occupational dose equivalent limit as set by 10 CFR 20, for the lens of the eye?

• A. 5 rem or 0.05 Sv
• B. 50 rem or 0.5 Sv
• C. 1.5 rem or 0.015 Sv
• D. 15 rem or 0.15 Sv

Answer: (D)

The lens of the eye is more sensitive to ionizing radiation than many other tissues, so regulators set a specific dose limit for it to reduce the risk of radiation-induced cataracts. The annual occupational dose limit for the lens is 15 rem, which is 0.15 Sv. Since 1 Sv equals 100 rem, 0.15 Sv converts to 15 rem. This lens limit is higher than the whole-body limit (5 rem) to reflect the distinct sensitivity of the eye while still providing a firm cap to protect vision. So, the maximum allowed dose to the lens in a year is 15 rem (0.15 Sv).