Eye discharge

Hello My 7 month old Australian Shepherd puppy had Hornhautentzündung about 2 months ago and the vet prescribed Cornegel. It got much better after 5days. But ever since she has a lot of discharge from her eye. It is mostly colorless, but of course overnight when it turns dry, it comes brownish. The white part of her eye also looks red most of them times, but she never shows signs of irritation ( touching eye with her paws). What should I do? Can it be because of dust and dry air ? Will using eye drops/gel help? Thanks a lot for your help and advice. Best Sara G