Quote - That last link is the clincher!... The iris is slightly concave...

If the last link is to be believed (it's only an artists impression), then it certainly is a clincher. In that image the iris is clearly and most definitely convex!

Also see this diagram http://www.waylandoptometric.com/WayOptCopy/eyeanat.gif. Or this one http://eyemakeart.files.wordpress.com/2009/05/human-eye-anatomy-diagram.jpg

Where I will grant you that there is a problem with my morph, is that although the iris has an overall convex shape, it does dip in towards the pupil. Perhaps the best analogy to the shape, though not quite exact, is a section from the front of a torus, rather than a section of a sphere.

Even before I saw these posts, I was feeling unsatisfied with my new iris morph, and have started working on a new version that is more toroidal in shape. I hope to post the new morph to the Developers site as "Iris-NewShape-LB.zip" in within the next hour or two. I will leave the old morph on the site over night for any one who wants it, and delete it some time tommorow.