Spongebob Eye Rig Help

[MicroSRB2]

So i was trying to rig Spongebob's eyes using the model from TCS ripped by Hawkodile. Whenever i copy and paste the driver onto the eye and move the eye bone i created, His pupil goes flying off into the next dimension. I was wondering if there was a way to slow down the UV movement, So the pupil would move properly. I sent some images of my problem.