Depends on the cause of the pinkeye. If it's for the stuff that is the actual cause, usually M Bovis and spread by flys, yes it will help. If it's from eye irritants from foreign matter, grass seed heads, or whatahve you, or if it's caused by other then M Bovis it won;t help at all. There are a couple of herds around here that vaccinate every year for pinkeye. In some years they still get it, in others they don't. We've never done it and with decent fly control and clipping the tall grass seed heads we haven't had any in years, knock on wood.