Ok sorry missed that part.

I just loaded the model in blender, normals are fine.

The only other guess is that the eye trans geometry is too close to the inner eye geometry and causing a conflict with the transparency. I can't spot anywhere that it actually intersects tho so I don't see why that should really cause a problem.

You could try creating a morph that shrinks the inner eye geometry or enlarges the outer eye geometry slightly and see if that changes anything.

Applying a subdivision level to the eyes might help, but they're already pretty high poly to begin with.

You could experiment with different material settings or you could swap her eyes with another figure's eyes.