Sorry to be pedantic, but a portion of UV light is non-ionizing and can still lead to photochemical reactions that aren't insignificant. For example 660nm light

Sorry to be pedantic, but a portion of UV light is non-ionizing and can still lead to photochemical reactions that aren't insignificant. For example 660nm light can be combined with methylene blue to make it toxic, which is taken advantage of in photodynamic therapy (PDT). I did some research on PDT as an undergraduate in university and the absorption of light by cells. I'm not in the medical field, but from what I understand most of the biological effects from lower energies just come from the heating of cells. Wikipedia has a very brief chart on the biological affects of non-ionizing radiation: https://en.wikipedia.org/wiki/Non-ionizing_radiation#Health_risks https://en.wikipedia.org/wiki/Non-ionizing_radiation#Health_... And don't forget simple facts like bright lights can blind people. Blanket statements like "(non-ionizing) light isn't dangerous" often have holes in them.