This is why UV light damage to cells is interesting. Rather than just nuking the whole cell, like a burn would, a UV photon can just cut a single DNA linkage, leaving the cell alive but broken, and subsequent attempts to replicate can either kill it or make it start misbehaving.

Well, that would explain why our skin can look so bad as we age, as most of the sagging and wrinkles are caused by sun exposure. Also I guess why chemo cancer treatments involving radiation (which chemo probably doesn't) can be so damaging.

Thanks for expounding!