Is it normal for eye color to change according to mood?

I've noticed that about ymself. Whenever I'm really mad, or in physical pain, my eyes seem to turn from a brown to a hazel, almost green sometimes. I'm sure it's rather wierd to most people because I know most people can't do that. Is there any explanations anybody can give?Is it normal for eye color to change according to mood?
well only thing i can think of it's like a chemical change.... When your mad or in pain, your body produces adrenaline and stuff, so maybe that effects it??? i've never heard of this, but then again i don't look in the mirror whenever i'm in pain or mad/angry, so idk... but it could happen i guess...Is it normal for eye color to change according to mood?
I don't have an explanation, but it's quite common, especially in hazel colored eyes. It changes when your crying, or tired, or had a good night sleep, the list goes on :)