Compared to the whole body limit, the lens-of-the-eye limit is...

• A. The same as the whole body limit.
• B. Higher than the whole body limit.
• C. Lower than the skin limit.
• D. Unrelated to total exposure.

Answer: (B)

The main idea is that dose limits are set separately for different parts of the body. The eye’s lens has its own limit because its tissue is particularly sensitive to radiation in a way that can lead to cataracts, so regulators specify a distinct allowable dose for the lens. The numerical limit for the lens is higher than the whole-body limit (for example, the eye lens limit around 150 mSv per year vs about 50 mSv per year for the whole body). This difference comes from using different dose quantities and risk assessments for an organ versus the whole body: the lens dose is measured as a specific eye-dose (Hp(3)) while the whole-body limit uses the effective dose for the entire body. In practice, you still aim to minimize exposure to the eyes as much as possible, but the regulatory numbers reflect how risks are allocated across tissues.