I read a lot of the reviews before buying this product and was worried about the red eye problem that many people had. My eyes did turn red after the very first time I used it but never again. I have been using it now for a little over 2 weeks and I can already tell a difference in the thickness of my lashes. It tells you to put it on your lash line, I wasn't sure what that meant when talking about your bottom lashes so I have only been putting it on my top lashes and that seems to be enough. I do notice that my eyes itch in the morning after having the product on overnight but that goes away through out the day. All in all I am happy with my purchase and the results are worth the very minimal side effects!!