Final answer:
Warfarin is a contraindication for cataract surgery as it is an anticoagulant drug that increases the risk of bleeding.
Step-by-step explanation:
A medication contraindication is a situation in which a drug should not be used because it may harm the patient or interact with other medications. In the case of cataract surgery, the medication that is a contraindication is Warfarin. Warfarin is an anticoagulant or blood thinner, which can increase the risk of bleeding during surgery.