I was given Topamax 100 m.g. to add to my PTSD cocktail of meds--I was still having terror nightmares and anxiety. It seemed to help as I recall 8 yrs later. After about 2-3 weeks, one day I started seeing silvery flashes at my eye perimeters when I blinked. The next day, every time I blinked, and sometimes when I didn't, I saw huge silvery flashes and was really worried..brain tumor??? Anyway, because the symptom was in the eyes, I got an emergency appointment with an opthalmologist (MD). He said my eyes were fine and asked about what medications I had recently added to the ones I used for depression and anxiety. Bingo! When I said Topamax, he jumped immediately and said, Oh, that's it! I've found about 20% using Topamax have acute symptoms. He advised me to stop the med immediately--whereupon in 2-3 days I no longer had the silvery flashes. Hooray! One more reason to read the fine print about a drug...get depth info from the web, not the package insert.