Olopatadine
"Here is a case of big pharma at its finest. $197 for a .5 ml bottle. Doc gave me two bottles sample. One was empty, one lasted a month. Same size. The one I purchased had TWO drops in it!! My insurance stopped covering it at the first of the year. I will never buy this again. I'm not sure it works for my condition, anyway as symptoms have not cleared up. Don't buy this."