I'm not confusing energy with intensity, but in a silly moment I got the word "photoionization" with photodissociation/photolysis. Yes, you need hard UV to actually eject an electron from its atom, but you need far far less energy to break bonds and damage DNA. Photosynthesis is all about redox driven by blue and red photons.

These are more than just bond rotations (with only slim exceptions, bond rotations have the same energy state) from photostimulation. You can flip cis/trans bonds (main mechanism of retinal), ring closing in vit D, and cause all kinds of increased free radical activity [1]. In particular, blue light interacting with certain chemophores, such as catechins, are relatively prone to photoactivation [2].

Ever seen polycarbonate that's been around blue LED light sources (not sunlight) for a very long time? It yellows. That's not "just adding heat", that's chemical bonds breaking.

Transparent just means the entirety of the body can be bathed in light.

[1] https://www.ncbi.nlm.nih.gov/pubmed/15797866

[2] https://www.ncbi.nlm.nih.gov/pubmed/29973539