Sorry for the withdraw of my original post.
I thought I wasn't familiar with the study and came to the conclusion I
already was.
However for those who are interested here is the link.
http://archopht.ama-assn.org/cgi/content/full/128/1/12
Don't mistake my intension, I have many doubts and I'm wondering if
others also have doubts and are willing to share theirs in this newsgroup.
For instance, the average axial length increase differences, in bifocals
without prism's and with that's to say zero (both 0,41) where the
difference in diopters is 0,96-0,70 = 0,26.
This is only one doubt.
Jan (normally Dutch spoken)