Technically his gaze can't pierce Pisces Australis because Pisces Australis is his Eye. It's quite hard to look at your own eye.
Seriously, that's quite cool. Maybe it's Morgoth's Eye; you know, everything Sauron did he copied from Morgoth, but on a smaller scale. Sauron's Eye is a joke compared to Morgoth's, the size of a Solar System.
Plus, Morgoth did get cast out of the World... I find this theory likely.
