During dental radiography, patients should be asked to close their eyes to reduce exposure to which organs?

• A. Lungs and heart
• B. Brain and spinal cord
• C. Skin and fingers
• D. Thyroid and lens of the eye

Answer: (D)

In dental radiography, some tissues are far more sensitive to ionizing radiation than others, so protecting those tissues is a priority. The lens of the eye and the thyroid gland are among the most radiosensitive structures in the head and neck area. The lens is particularly vulnerable to cataract formation from radiation, and the thyroid can accumulate dose from scattering even when the beam is focused elsewhere. That’s why efforts to minimize dose emphasize shielding and limiting exposure to these tissues. Asking the patient to close their eyes helps reduce exposure to the ocular lens and surrounding eye tissues from scatter radiation, and explains why this measure targets the lens of the eye and the thyroid for protection. The other organs listed are either well shielded by anatomy or receive negligible dose during standard dental radiography, so they’re not the primary concerns in this context.