Does anyone know what to do about this?

I've had a thyroid problem for a number of years due to an infection, and while that has largely resolved, it has left dark double rings under both eyes that seem to be permanent. These rings are very noticeable (I'm not just angsting here), and have the effect of making me look very degenerate. It's actual discoloration, not "bags". On bad days, the entire area around my eyes is discolored (meaning the top lid, too, is dusky). It's bad enough that it's drawn fire from my bosses that I need to start "taking care of myself better" and insulting remarks about how I need to "make myself up".

Thing is, I DO make myself up, with very thick concealer. It just doesn't do much for me because these rings are very noticeable. I've also tried rubbing vitamin E around my eyes for several weeks now, but the rings continue to sally forth. Vitamins aren't working. More sleep isn't working. Eventually, I just started walking around with my hair over my face since it's obviously such an issue to larger society.

There's got to be a better solution.

What creates these rings, and how can I diffuse it? Any ideas?