I've used Restasis myself for several years and it takes awhile to work when you first start it, a couple of weeks, at least. Also, it is not without side effects. I get a burning sensation and red eyes from it, so only use it once a day. I also use the Genteal for comfort. One of our dogs gets seasonal alergies and sometimes needs Rx drops (forget which kind) and sometimes Genteal, but she has her own bottle. We don't share.:W