I had a problem with the Mesh Deform Modifier - but I fixed it. I found that if I tried to set up the Mesh Deform modifier with the Mesh Def object deformed (the lattice modifier visible) then the results were off, or not visible. So just a note, make sure you set up the Mesh Deform with an un-deformed Mesh Def object and you should be fine. Needs some tweaking but I now have a usable eye! This was a great course!