From what I can see dispersia dust makes only warp scrolls.. so I'll produce them before long underground treks.
As for the light thing - the emit light scroll is actually main issue here. It makes you light very brightly while areas around that light can be very dark which creates large contrast difference. And since both minimap and area map is on left and right side of screen it's near dark areas.
It's actually much better for me to explore in the dark if there is nothing dangerous like bosses around. And my monitor is already set to quite dark in general.
Part of this maybe fact of playing on 16:10 wide screen which gives very wide field of view so emit light doesn't cover whole screen or some magical dynamic contrast thing from my LCD.
Thanks to all bug hunters for their hard work