30daysofbatis interviewed Dr. Michael Pollmann from Zeiss. The talk is focused on the 40mm Batis lens. Mr. Pollmann said this about the EyeAF support:
The Eye-AF issue is an example of “hindsight is 20/20.” We checked the AF accuracy and repeatability in all the standard AF settings – AF-S, AF-C etc. – prior to the market launch. The lens worked perfectly. In principle, when using Eye-AF, the communication to the lens is no different from “standard” AF-modes. The camera decides the best focus lens group position. However, in this case, they were visibly different. So we fine tuned the lens control parameters, and now the Eye-AF works fine. And you can be sure that, in the future, the Eye-AF will be tested with every new lens prior to bringing it to market!