I had IPL on my eyebrows 1 year ago – only 2 sessions. I now only have the medial part of my eyebrow on both sides because she removed too much hair. I was very upset and she assured me they would grow back. They haven’t. Will they eventually?
Essentially, the person that did the hair removal on your eyebrows screwed up and got rid of too much hair. If you haven’t seen any regrowth after a year, it is likely that they may not grow back on their own. If they do not grow back, hair transplants into the eyebrow will work well. For those curious about IPL, see the intense pulsed light listing at Wikipedia.