What Risks Can Occur if Pain Medication Were Taken Two Days Prior to a Blepharoplasty?

This depends entirely on the type of pain medication taken.
The use of Tylenol and narcotics shouldn’t cause any significant problems.
However, drugs like aspirin and Ibuprofen represent an area of concern because
they may cause bleeding. For this reason, surgery should be delayed if these
medications have been taken within 48 hours of blepharoplasty surgery.

                  We
generally recommend not taking aspirin for 10-14 days and Ibuprofen for 3-5
days prior to surgery. This approach minimizes inter-operative and
post-operative bleeding and lowers the complication rate for this procedure. 

If you took Narcotic pain meds (Tylenol #3, or Percocet), there is no reason to be concerned. If you took Aspirin, there is some reason to be concerned because Aspirin has a very enduring effect on platelet function; most surgeons would probably cancel Blepharoplasty in this situation, especially if you are having a lower lid Blepharoplasty.  Although it is not ideal to take Ibuprofen (Motrin, Advil), it is generally out of the bloodstream in 6-12 hours.  Naproxen (Aleve) has a half life of 12-16 hours, still allowing you to have surgery.

Pain medication will not create a problem in a patient having a routine blepharoplasty.  Aspirin based meds do effect clotting but their influence on surgical complications, in my opinion, are way overrated.  Nevertheless, this should be made clear to your surgeon who may want to postpone the operation for a few days until the platelets are unaffected by the aspirin.