The contact solution works great at first. After about two thirds of the bottle, it seems the special case doesn’t neutralize the the solution causing burning in my eyes. I bought a two pack thinking there would be two cases, there’s not so that was a waste of money. I would recommend selling a one pack with two of the containers, so it last for the whole bottle. Do you sell just the cases? That way I could use the whole bottle of solution without issues. Otherwise I think the product works great, the cases just don’t neutralize the solution for the duration of one whole bottle. Thanks, Dan