Delayed Tear Trough Bruising - 5 Weeks Later! Seems Strange (Photo)

Although bruising occurs with injection of the tear troughs, it is usually immediate.  If the area was fine initially and a month later this occurred, I would seek an evaluation as soon as possible.  I would be worried about an infection at this point especially if the area is hot to the touch.  If it is an infection, treatment should be started right away.  

While swelling and bruising right after fillers is normal, it is abnormal to have everything be ok and then suddenly awake to find something like this. You need to be evaluated in person for a possible infection or reaction. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."