Headlight restoration is a process that involves cleaning and rejuvenating the plastic or polycarbonate lenses of a vehicle's headlights. Over time, the plastic lenses can become cloudy, yellowed, or hazy due to exposure to the sun's ultraviolet (UV) rays, environmental contaminants, and general wear and tear. This can reduce the effectiveness of the headlights, making it more difficult to see at night and diminishing the overall appearance of the vehicle.