It could be that the studio lighting in the Stern interview was particularly flattering and that he had good makeup on. Based on these pics, I'm standing by forehead botox, but no brow lift. The position of his brows and his upper eyelids haven't changed. Maybe veneers, I can't tell, or just teeth whitening. Maybe just clean livin'! The lighter hair brightens his face. He had those dark eye circles in the 70s, but he was hot. He has managed to stay nice and thin.
I'm spending way too much time on this.