Is this Tyndall effect or Hemosiderin Stain? (photo)

If you're seeing dark circles u set your eyes 6 months after your tear troughs were injected,  it's very likely that is time for re- treatment since HA fillers typically last only about a year and some of the material is recovered by now. All the best from Boston,  Dr. Onir

Thank you for your question.  It is helpful that you provided a photo.  However, it would be even more helpful to have a photo of both eyes to compare.  You mentioned that it looked good at first.  Can I assume that you did not get a bad bruise after the treatment?   Assuming that is the case, it appears as if you have a combination of the Tyndall effect as well as some baseline pigment in the skin under your eye.  If that is the case the Tyndall effect will go away as the filler slowly dissolves but the baseline pigment will remain.  Talk to your doctor.  There a prescription level creams that can help with your baseline pigment.