The Implosion of the Planet Paragangia Edit
The Shattering coincidentally occurred at the same time that Leviathan was being created so it was about 3 generations prior to the beginning of the Destiny of Dreams story [prior to the time of Jason Scott-Harris.]
The planet imploded because instead of building on the surface, and terraforming the barely habitable planet, as the Prophet Paragon had covenanted to do when lead there by inspiration,
Teraforming began with Paragon but after the death of Paragon they began to neglect the terraforming turning their attention to other interests and they tunneled inside the planet, and then built above the tunnels, turning the whole thing into something like a giant space station, until the weight of what was above the surface got to be too much for the undermined globe and the whole thing collapsed suddenly into rubble killing everyone in the planet.
the planet also had a dreamstone layer like Terran 8 and this was shattered as well.
The color-change of Paragangian's eyes. Edit
Paragangian eyes change color when they are hurt or stress or very upset ...like grey roots spreading from the center, as Allissa descrbed it...
this was already a genetic trait before the shattering, but after the shattering the story arose that this was given to Paragangians as a reminder of their shattered planet so it came to be known as Shattering. or perhaps the eye thing was called that and they named the event after they eye thing.