It is the clearing of condensation on the inside of car windows
Try cleaning the outside of the headlamp first with toothpaste... 99% of the time it appears as though its on the inside but its on the outside.
Possible answerIf your headlamp is like mine, a Chevy Malibu, then there's a small vent hole with a tube coming out. Make sure there's no obstructions in the hole or vent.
You are going to have to replace the entire Headlamp Assembly, very expensive.
Condensation.
Drink it
Energy is transferred to a headlamp typically through electrical wiring connected to a power source such as a vehicle's battery. When the headlamp is turned on, the electrical current flows through the wiring and powers the light bulb or LED inside the headlamp, producing light.
To prevent condensation inside windows, you can improve ventilation in your home, use a dehumidifier, and ensure proper insulation around the windows.
If there is water in a headlamp, then you can carefully drill a hole in the plexiglass front close to the bottom to let the water drain out. Then the hole can either be sealed, or left open to let any future water drain out.
Condensation forms on the inside of windows when warm, moist air comes into contact with a cold surface. To prevent condensation, you can improve ventilation, reduce humidity levels in your home, and use a dehumidifier if necessary.
To effectively remove condensation inside windows, you can improve ventilation in the room, use a dehumidifier, or apply a commercial anti-fogging product.
To prevent condensation inside your tent, ensure proper ventilation by keeping windows or vents open, avoid bringing wet gear inside, and choose a campsite with good airflow. Additionally, using a tent with breathable materials can help reduce condensation buildup.