Recently I learned something really interesting about people with blue eyes. Extensive research has been done and it turns out that all people with blue eyes can trace their ancestry back to one person--that's ONE person--who lived 8000 t0 10,000 years ago near the Black sea.
Because it's caused by a mutation and is recessive, it turns out that there are less and less people being born with blue eyes, at least in the US. In the United States, the number of people with blue eyes has dropped from one in two to one in six because the brown eyed gene is dominant.
Europe is where 95% of people with blue eyes are born and Europeans are a great anomaly because, on all other continents, everyone has darker skin and brown eyes. Once, all humans were born with brown eyes. Indeed Europe is a great mystery in this respect because of our African ancestry, though the theory is that our skin changed due to the harsher weather and need to absorb Vitamin D, easier with fair skin.
Another theory states that the European differences have resulted from inter-breading with Neanderthals--though there is no evidence of large scale breeding taking place between homosapiens and them.
Not sure where that puts me and others with hazel eyes, though.