I have dark circles under my eyes too, definitely what you'd call racoon eyes. I'm 22 years old, and it's really bothering me. At first I thought it had to do with my smoking habit, I used to smoke half a pack a day. But my friends who are my age smoke even more than I do, and they don't have even the slightest puffiness or dark circles under their eyes, this was one of the indications for me that I was somehow sick, but I didn't know what I had at the time. I started to notice it two years ago, which is around the time I contracted Lyme disease, so yeah, I do think Lyme can cause it. I'm pretty sure it has to do with inflammation and lack of sleep. And the lack of sleep only makes the inflammation worse, so it's a constant cycle. I've been on oral antibiotics for only 10 days, and they're starting to become much less noticeable than a week ago. I'm not sure whether that's due to the antibiotics killing off the bacteria, or because of the fact that Doxy is an anti-inflammatory. Either way, it's working.