Headlamp moisture - Headlamp assemblies are vented to the atmosphere to accompdate changes in temperature with the assembly. The result of this is that humidity in the headlamp atmosphere can condense when the temperature falls below the dew point. It is cormal for a mist or fog of dmoisture to condense on the inside of the lens. Moisture levels in the headlamp become abnomals when there is a large amount of water drops forming on the lens, as in the photos below.