Hyper-rapture was a supposed form of madness acquired from staring into hyperspace for a prolonged time. To prevent this, standard procedure for Imperial ships was to opaque the transparisteel slabs while traveling through hyperspace.

However, Darth Vader enjoyed staring at the kaleidoscopic and swirling patterns of light, and Cronal found it soothing to stare into what he thought of as the emptiness outside the universe.