Angels' Eyes also helps to eliminate staining around the mouth and their coats due to licking. Other products are topical requiring high maintenance and yet will only remove the tear stains temporarily causing it to return worse than before. Angels' Eyes starts working before the tear stains begin and never adds food dyes or wheat which can have negative effects on your pet. As you keep trimming the stained areas, the newly grown coat will be totally clear.   The growth pattern of your pet's coat will determine if it will be completely tear stain free anywhere from 3 to 5 weeks.