Esther, On the eyeball I found white highlight made a difference in how shine worked on eyeballs, but w/ white it was worse on skin...seemed harder to control. I know specular controls can be a bit more mysterious to understand than say diffuse.So what I said earlier probably doesn't hold true. Tho I didn't get a plastic look at 7% shine w/ black highlight.

No need to think outside the box....
    Just make it invisible.