The reason for Ephwrath's warning becomes clear very quickly, even for those who manage to turn away or shield their eyes. As the light emanating from Ember's magic missile touches the glassy orb at the center of the room, there's a brief moment where the glow lights up only the orb. The orb itself glows with a building intensity and then the radiance bursts out in all directions. It strikes the crystals covering the walls and floors and amplifies further, filling the room with a glow so intense that it can be sensed even through shielded eyes. There is no warmth or physical sensation, simply an explosion of light.
Willitan, Ephwrath and Verrian are not quite quick enough to cover their eyes, and the searing light overwhelms them. With their eyes open, everything they see glows with an aura so painful it forces them to close their eyes again. Even then, flashes explode behind their eyelids, dancing and swirling, but at least it's not physically painful.
Yelnar and Ember can still see, but even despite their quick reactions, they are forced to look around through squinting eyes.
Only Elora retains her normal sight.
