The premium microfiber cleaning cloth or microfiber drawstring bag included in the package in which you received your Parallel sunglasses are best for keeping your Parallel lenses in top shape. Carefully blow or brush off any sand or grit you see on the lenses and then gently rub the lenses with the microfiber cloth to remove smudges or smears.
Always keep your Parallels in the protective zippered case they were shipped in.