Why and how do some peoples eye color change?

I don't know why or how, but I will also watch the question for possible explanations.


My eyes also change color, often it seems to be associated with my mood.


My eyes are hazel colored, a mix of green and brown and tend to turn more green with certain moods.Why and how do some peoples eye color change?
Great question! I have that happen and have often wondered why. My eyes turn a brilliant shade of green when I cry. Not just because I am upset but anytime they tear. I am going to keep tabs and see if anyone actually knows the real answer to this.