Spray the lens with compressed air. Hold the tip of the spray can 6 to 8 inches away from the lens. This removes most dust and debris without scratching the surface of the lens.
Mix a solution of 1 tbsp. of dish detergent and 5 cups of warm water in a plastic container. Stir the solution with a spoon until the dish detergent completely dissolves.
Pour the solution into a liquid spray bottle.
Spray a thin layer of the solution onto the solar lens. Let the solution soak for 5 minutes. Do not rub the lens.
Pour distilled water into a different liquid spray bottle. Spray the solar lens with the distilled water until there is no remaining detergent. Excess detergent damages the solar lens.
Repeat Steps 4 and 5 until the solar light is fully cleaned.