More than two million bottles of eye drops were voluntarily recalled this month after the discovery of a “foreign substance” that might have compromised the safety of the medication.

Prescription prednisolone eye drops manufactured by Lupin Pharmaceuticals were recalled due to possible contamination with an unidentified foreign substance.

The class II recall of the prednisolone acetate eye drops -- used to reduce inflammation after eye surgery or for allergic and other conditions -- is the second-highest risk recall for the agency beca...