Complications of Eyelids, blephoplasty plastic surgery are very rare, but like any surgery, it also contains some post-operational risks.
Some possible risk s of blepharoplasty:
Imperfect operational Results : Following an unexpected reaction of tissue or unusual scar phenomena, requires an "surgery"
Hematoma: may require evacuation
Infection: exceptionally possibility of conjunctivitis
Healing Anomalies : very rare
Epidermal Cyst: easy to remove without consequence on the aspect
Troubles of the secretion of tears: existing of persistent tearing decompensation or "dry eye"
Ptosis: pre-existing deficit increased by intervention
Lagophtalmie: transitional inability to close eye
Eye round: ectropion following the removal of the skin to the lower eyelid
Diplopia: double vision which is rarely observed
quite exceptional Hypertension and blindness , a few cases reported in the international literature
We should not overstate the risks, but simply that a surgical operation, even has a simple part of unpredictable risks. By finding of qualified plastic surgeon you can assure that it has proper training and skills to avoid these complications, or deal with them effectively.