These lenses look like thick sheets of black obsidian mounted in a leather strapping that can be fastened around the head. The design is slightly strange and looks like the device of a mad scientist, though they are not; more accurate would be the device of a mad necromancer. When first looking through the lenses, the wearer must make a Will save (DC 20) or go permanently blind. When worn for more than 10 rounds a Will save (DC 20) is needed to avoid insanity and blindness (one check for each) each round. Each consecutive round past 10 incurs a -1 penalty to the Will saves.