Why is melanin useful?

Question

Why is melanin useful?

Answer 1

Melanin gives us the skin colour.

Answer 2

Melanin is useful in several ways in that it gives us skin and eye color, for one. But also it is vital in blocking UV solar rays.

Answer 3

Helper is right, melanin absorbs UV radiation, but the reason is because this could cause major damage to cell machinery.  This sort of radiation can kill cells, or mutate them, sometimes leading to skin cancers.