Figure 1. A level 4 cataract as viewed by slit lamp seven months post-irradiation. This cataract developed over a period of 30 days at seven months post-irradiation. It was not present at six months, and the same lens was scored as 1.5+ at that time. The same minimal degree of opacity (1–2+) was also seen in the non-irradiated control mice at that age.