Eyes can change colour, but it takes a long time for the change to happen fully and is linked to your growing (hormones for example, no one is 100% sure why)
Eyes reflect a certain amount of light, obviously, and because of the unique construction of the eye (it's sole purpose is to take in and filter light) varying intensities, hues and natures of light reflect differently, causing your eyes to look a different shade. Just being in a different room and wearing different coloured clothes changes the way light hits your eye.
I did a lot of research after my ex told me, straight faced, that she could change her eye colour at will and I called bullshit. Hope this helps.

Maybe once you've taken a few, everything looks like that

Well I know a bit of Pokey always makes my day 10x better!

This is far more than 368 hotdogs, this is constant eating for years. You'd think she'd stop when it became hard work standing up from a chair, but she powered through and kept on eating. She's dedicated at least.

I'm English.... I have no knowledge of your customs, they seem strange and alien to me

You're welcome, I like to acknowledge badassery in all it's forms

What if they have a 3GS? With only one camera?

They'd all get it though, I'd like to offer my services as a conjugal visitor for all of them

Also leaves you pretty much devoid of body hair and, more open to the mutations that cause cancer......

(Katy Perry, none of the others before some smart arse makes a comment to that effect)