I completely understand!! I've talked to fellow swimmers in the other lanes about this and the dark suction circles just happen. There's not much to do about it and no, there's no permanent damage after years of swimming, as observed on the swimmers that have been at it for *years*. I had to start swimming evening hours to avoid the funny looks from co-workers. Have a good swim!
I am not convinced that there is no permanent damage. I am 49 and was a dedicated long distance swimmer for 25 years....sometimes I used masks when I found the goggle marks too much. I few years ago I settled on the AquaSphere Kaiman goggles, in size small. When I turned 47 I noticed bags under my eyes with huge circles that did not lessen for several months. I now have puffy bumps on the top of my cheeks (I believe they are called malar something or other) that I cannot help but attribute to the years of the pressure of the goggles I wore. Some people get these removed with plastic surgery. None of my siblings have these puffy bumps - it seems to make sense. I stopped swimming so much two years ago and when I do, I only wear a mask. Good luck!