"double-strand breaks...are caused by ionizing radiation, including gamma rays and X-rays." vs. "UV radiation causes two classes of DNA lesions: cyclobutane pyrimidine dimers (CPDs, Figure 1) and 6-4 photoproducts (6-4 PPs, Figure 2)."
more energy in a light wave the more likely it is to cause cellular (DNA) damage.
Ultraviolet has less energy than X-rays (it goes through your flesh to see bones!)
Order of light strength (cell damaging capability)