The Black is the pupil. The grey you see when the pupil pins is the iris.
I have brown eyes, my iris is brown but the black in the middle is my pupil. I could go on to say the pupil isn't actually black, it's a hole into your head. But that's another topic of conversation, lol.
Birds can't rotate their eyes. I can look up without moving my head since my eyes rotate. Birds have to do the ever-so-cute head tilt to see above them. That's why they are built to rotate thier heads so far, unlike humans.
Aha, just found an interesting blurb on pinning. I should have looked for it before. ^_~
http://www.parrotchronicles.com/departm ... havior.htm
This next one is more extensive, and more medical. ^_^
http://www.birdsnways.com/wisdom/ww31eii.htm
...nictitating membranes... I've always loved how that sounds when said aloud.
![Laughing :lol:](./images/smilies/icon_lol.gif)