The Fire Strategy Run the tip of a flame across the internally of the lens right until the glass turns black, the flame will remove the substance off. An lighter or even a tapered candle performs well. Just after the inner surface of the mask lens is completely black, pause for the mask to chill and wipe away the soot with a soft towel. Duplicate this task two or three cycles until eventually it is difficult to get the glass to turn black. Do not admit the glass to turn seriously hot, and dont use this trick on masks with plastic lenses (they will ruin). Make sure to confine the flame from the soft silicon skirt of the mask given it will melt with exceptionally little heat.