I have been using the generic version of Latisse since April 2010. At first, it caused my eyelids to itch. I have green/brown eyes and there has been no change in eye color. I bought very small eyeliner brushes to use with the product. I put one drop in the cap of the bottle and apply across my eyelids; the remainder I use on my eyebrows. I use it every night before bed (unless I'm too tired or forget). It took about 4 months before I got significant results.
My light brown sparse eyelashes are now a little darker and about 1/4 or so inches longer. I still need to use a decent amount of mascara, but I no longer need an eyelash curler. There was a period about 3 or 4 months ago where my lashes became a bit sparse in some places, but I continued to use the product and the problem went away. I've noticed some darkening of my upper eyelids but I use light eyeshadow to mask that. No one has ever commented on the darkening.
If you plan on using Latisse, I recommend that you are diligent about applying it every single night for several months, otherwise you may not get the results you want.
The downside to the product is that you have to keep on using it or your previous lash cycle will return and you'll go back to the lashes you had before. Another thing is that my lashes are not as thick as I had hoped they would become. Although I apply some of the product on my eyebrows too, I've seen very little if any change in the thickness. I will continue to use the product as long as I can find it at a reasonable price.