Thanks guys.
Rich, Yes I took the shot. I held held the camera with the front element facing towards me. I switched autofocus on and looked into the lens. At certain points you see a perfect circle of light. that means you're seeing through the lens, and then the light that is being relfected off the mirror and then through the view finder. You don't see any detail of course but you can see movement if there's anyone behind the camera moving. Once I heard the focus lock beep at me I took the shot and then keeping the camera where it was and by making very minute adjustments left, right up and down I knew at some point, I'd get the iris fully in the frame.
Took quite a few attempts for sure.
A better way of doing this would be to put the camera on a tripod, hang a weight on a piece of string from the cross brace in our conservatory at the exact height of my eyes, get focus on the weight and then move myself and in particular one of my eyes into the position the weight is in and use remote release. that would probably guarantee a successful image each time.
I also should bounce the light or have the flash off camera to avoid getting the white of the softbox in the eye.
