What is the federal annual dose limit for the lens of the eye?

• A. 5 rem/yr
• B. 50 rem/yr
• C. 15 rem/yr
• D. 25 rem/yr

Answer: (C)

The lens of the eye is highly sensitive to ionizing radiation, and cataracts can form at relatively low doses, especially with cumulative exposure. To protect vision, regulators set a specific annual limit for the eye rather than just a general whole-body limit. Historically, the federal occupational dose limit for the lens of the eye has been 15 rem per year (150 mSv). This cap helps ensure that exposure to the eye doesn’t accumulate to levels associated with increased cataract risk, even if other parts of the body are protected or exposed differently. For comparison, the whole-body limit is 5 rem per year, and limits for extremities or skin are higher (about 50 rem per year), reflecting different tissue sensitivities. Modern standards have moved toward lower, more unified eye-dose limits, but the 15 rem/year figure represents the traditional regulatory value for the lens.