The correct answer is option 1: Eyes. When it comes to the effects of nuclear radiation on the human body, the eyes are the first highly affected part. Exposure to high levels of radiation can lead to various eye issues such as cataracts, retinal damage, and even blindness. These effects can occur due to the sensitivity of the eye tissues to radiation. It is important to note that other parts of the body, such as the lungs, skin, and bone marrow, can also be affected by radiation, but the eyes are particularly vulnerable. Therefore, it is crucial to protect the eyes from radiation exposure through the use of appropriate protective gear in situations where the risk of radiation is high.