Good thinking! If the lens cover is glass or a hard surface, dust should not be an issue. But, if it is, set up an air line with momentary electrical control valve. My Lexan windshields can be scratched easily so one of my machines, the Barko 937, has an "Air Knife" cleaning attachment that blows air across the front glass when the switch is held down. This removes heavy dust/debris without risk of scratching the delicate surface. It's not as good as a wash down but it gets me by on a dusty day with lots of sun.