How to repair procedural texture for animation? I made an eye and for texturing I used a procedural approach. It looks fine when the character is in rest position, however when in pose position the whole eye turns red (the materials don't work well anymore?). The file can be downloaded here: https://www.dropbox.com/s/oy4utqa1l0grppk/blendstackexhange.blend?dl=0
 I have 2 materials: one for the sclera and one for the iris. The shape of the eye is the following(the selected part is the iris):


Material preview in edit mode:

Is there a fix for this? Here is a picture of the eyes in rest and pose position:

EDIT:
Here is my node setup:
The iris:

And the sclera:
if you uncheck this (bind to vertex groups), it works. Although i am not sure whether you need this... ;)