OK so there is now a fix for the Daz Studio eyes. Daz Studio along with Genesis is an excellent option as to character model development that can make us of the Metahuman resources like materials but some of the mesh objects, like the eyes, are a bit to complex that needs to be reconfigured to make use of the material like the eye shaders.
Now there are some useful resources available that remaps the objects so materials for the eyes can be harvested.
