Peter Evans , Aug 11, 2005; 04:39 a.m.
I take your word for it that the nose is better focussed than the eyes: at this magnification, it's hard to tell.
Yes, if all other things had been equal, the eyes would have been in focus at f5.6. The problem is that the background would have been better focused as well, and thus more distracting. For something like this, I'd normally use something between f2 and f2.8.
Of course f1.4 is better still, if you get (or the autofocus gets) it right, but chances of failure are higher. As an extreme, I have an 85/1.2 lens (not EF): when the gods are smiling on me it's wonderful, but it does bring a lot of duds.