How exactly does UV rays from the sun affect hair colour?

I know it does, but I just want to know the details on how %26amp; why it does. %26amp; Could you please cite your source? I want to read more about it.How exactly does UV rays from the sun affect hair colour?
Melanin filters out UV radiation, but the melanin in hair follicles, particularly in light hair, actually increases the sun damaging effects of UV rays and causes cell death in the hair follicle.





thank youu ^_~How exactly does UV rays from the sun affect hair colour?
Well UV rays are part of the electromagnetic spectrum. The different rays in the electromagnetic spectrum have different penetating powers depending on their frequency. As the frequency of UV rays is relatively high it has enough penetrating power to cause gene alterations or mutations. These gene mutations may cause hair colour to change.
Interesting question. My hair does that every summer! I found a good answer here:


http://www.madsci.org/posts/archives/feb…