Dr. Bates says black circles underneath the eyes and wrinkles are caused by eyestrain. Most people who are myopic, hypermetropic, astigmatic etc have dark circles under their eyes and the worse the eyesight, the worse the circles. Glasses, contacts, and I assume lasix do nothing to relieve the eyestrain, just sort of make it permanent. The only way to get rid of the circles is to relieve the eyestrain.
I'm not saying this is the cause of your circles only that it is a cause, I am very myopic and I'm sure it is the cause of my circles.