How Much Bruising Should I Expect from Under Eye Filler Injections?

Thank you for your question, devika! Bruising is always a potential with any filler treatment. If a cannula is used, bruising is minimized when compared to injecting with a needle. You are able to apply makeup gently to the area the next day, so taking time off of work may not be necessary. Try doing the treatment on a Friday so you have the weekend to recover. 

Bruising and swelling depends on the patient.  Any time that filler is done, there may be bruising or swelling.  I recommend using an ice pack to the area for several hours after injection to help with bruising and swelling.  It also helps if you keep your head elevated for several hours after injections.  It is also best to refrain from anything that is strenuous that may elevate your blood pressure.  I recommend not exercising for 24 hours after injections.  Most patients have minimal swelling or bruising and do not take off work for injections.  You should visit a skilled Plastic Surgeon who has experience with facial fillers and injections to see what his recommendations are for you.

Thank you for the question. I am sorry to hear about your bruising.  There are steps that can be taken to reduce the swelling and bruising.  
Before the treatment, it is advised that you avoid medications and substances that increase the risk of bruising.  The patient may be asked not to take aspirin or NSAIDs for at least 7 days, unless discontinuation of these poses a significant risk.  Herbal medications (such as St John’s wort, ginkgo biloba, vitamin E, garlic, ginseng, fish oil) that predispose to bleeding and bruising should be withheld.  Preoperative ingestion of some homeopathic medications such as arnica may reduce bruising, although further investigations are needed to confirm this.
It is also imperative that you choose an experienced injector who uses a technique to minimize bruising.  This is an operator dependent procedure and so you need to be in safe hands.  This is particularly important when injecting under the eyes as the skin is thin and there are multiple blood vessels which can be injured and cause bruising.
After the procedure I also advise my patients to ice the area for up to 10 minutes every hour.  Reusable ice packs can be used or a bag of frozen peas can be used to mold over the area.  A short course of steroid can also accelerate the healing process.  Anectotally, Arnica forte can be used to prevent bruising, but no definitive evidence exists to suggest that is always successful. 
If you would like to learn more about injectable fillers I recommend an in person consultation with a board certified dermatologist with cosmetic training.