I have a purple bruise that looks bad under my eye after filler.

Bruising after injectables is quite common and can last 1-2 weeks.  If you are concerned follow up with your treating physician.

Avoiding bruising with the use of canulas is the most important thing in general. When using needles there is at least a 5% risk of significant bruising in the under eye area. Once there bruising can take 2-3 weeks to resolve. Lasers can be helpful and, if used right away, heparinoid cream can help as well. 

Thank you for sharing your question and I am sorry to hear of your bruising.  Bruising in most people will last around 14 days depending on the initial discoloration.  I would recommend warm compresses, arnica, bromelain, and eating dark leafy green vegetables as ways to hasten its resolution.  Additionally you may wish to discuss the use of cannulas with your undereye injections with your injector at your next treatment.  Hope this helps.

Thanks much for  reaching out.  natural lifespan of a bruise can be anywhere from 7 to 21 days. The skin underneath the item to hold onto the bruise color little longer than the rest your body.  The final stages will be yellow.   You can take Arnica pills as well as Bromaline and that may help quicken its resolution 

Thank you for your question.  I understand your concern about the bruising.  Bruising and swelling are common after the filler and Botox injections, but they should subside in about two weeks after the treatment.  Often it's better within a week.  Continue the Arnica.  Avoid hot environments and vigorous exercise.  I hope this helps with your concern.  Wishing you the best.