Cloudy headlights aren’t just unsightly to the eye, it can also reduce the amount of light from the headlight. Thus making it dangerous to drive in the night. When left untreated, this can be an advisory or even a failure on your car’s MOT. When it gets to this stage, most people will buy new headlights, which are very expensive and not always necessary. It is possible to rectify the problem by carefully wet sanding and machine polishing the outer casing of the lamp before protecting it.