Several years ago, I had conjunctivitis, and my doctor prescribed an ointment. I used the ointment as instructed, and my conjunctivitis remained and spread to the other eye as well. The doctor prescribed the ointment again. I used it as directed. Minor improvement, but then returned full force. At my wit's end, I bought Rich's MSM water drops, and applied several times a day for a week. Conjunctivitis disappeared and never returned. I now use the drops when my eyes are tired or itchy, and they work perfectly.