Figure 6. Increases in cortical DNA and ROS following X irradiation at 3 months of age. Vital staining of fresh lenses for ROS and DNA were carried out with the same stains shown described in the legend to Figure 5. The data are presented as per cent of 3-month controls (see Methods). Red circles are for lenses X-irradiated at 3 months and green squares are for unirradiated age-matched controls. Error bars represent standard error of the means, and stars indicate a significant difference from control values using 1 tail Mann–Whitney test (**, p<0.01). Each point represents the mean of 4–6 mice analyzed.