I have 2 wonderful persians and my female, Lady Juliett, has trouble with eye crusting and mucous. I have tried several products including veterinarian and herbal. Eyes So Bright is the best. I like just putting the liquid on a cotton make up pad or square and gently cleansing the eyes. One product I tried was an eye dropper and Lady Juliet hated me trying to put it in her eye. This is so much easier and within several days of the first application her eyes have improved. Thanks for the great product.