I used latisse 6x over the course of 3 weeks, following the exact directions with one drop on each brush, and to stroke it over the eyelid like applying eyeliner. Within 3 weeks, on both of my blue eyes, there are brown spots on the iris of each. These were not there before, and I never had any traces of brown or green prior to starting to use latisse. I have stopped completely, but I would highly caution advising that this is a rare occurrence. It can absolutely happen with very minimal usage.