Visible light penetrates the skin rather well. That's why you can see blood vessels and bruises and strong lights through closed eyelids. UV penetrates the ski

Visible light penetrates the skin rather well. That's why you can see blood vessels and bruises and strong lights through closed eyelids. UV penetrates the skin even better, and is by far the more dangerous of the three spectra you mentioned. That's why almost all animals produce melanin - the stuff that gives our skin, hair and eyes their color. It's nature's UV blocker.