Some houses of Drow have not laid eyes on a surface dweller in many generations, so they have forgotten that not everyone can see perfectly well in the gloom of the Underdark. Other clans have had to deal with repeated incursions from above and have come up with several ways to deal with them. Some drow torturers enjoy using flashstones in conjunction with conventional techniques, conditioning the victim to equate bright light with pain.
The flashstone is a hard, shiny pellet that glistens in light and glows slightly under both normal vision and darkvision. It is the same size and shape as a sling bullet, and it is used in a sling as often as it is thrown. When a flashstone strikes a hard surface, it vaporizes instantly, releasing a blast of light (15 foot-diameter circle). Creatures caught in the blast must make Fortitude saves (DC 16) or be blinded for 1 round. Once the 1-round blindness has passed, the creature suffers a -2 penalty to Spot and Search checks for one hour while its eyes recover.