Cataract resultant of Nagasaki atomic bomb

One of the effects of radiation exposure over 1 Gy is an increased incidence of cataract formation in the years following exposure. When exposure reaches 5-6 Gy, there’s a spike in cataract cases within the following two years.

Ionizing radiation does the majority of its damage to dividing cells. Because the cells of the eye divide around the periphery (outer border) and move inwards toward the center of the lens as they replace old cells, the initial damage from radiation is not concentrated in one place, and lens opacity does not immediately occur.

Acute radiation syndrome in Hiroshima man

Acute radiation syndrome is the short-term (first months) effect upon the health of those exposed to high levels of ionizing radiation. Depending upon the dosage of radiation received, the symptoms can vary widely, but some of the most common effects are moderate to severe leukopenia (decrease in white blood cell numbers), purpura (the purple spots under the skin caused by subdermal hemorrhage - a result of platelet destruction), hemorrhage (general hemorrhage - again, because of platelet destruction), nausea and vomiting, and epilation (hair loss).