This medication is used to treat bacterial infections (such as blepharitis, conjunctivitis) of the eye and the skin around the eyes (such as eyelids). It is also used to prevent infection after eye injury or surgery. It belongs to a class of drugs known as aminoglycoside antibiotics. Gentamicin works by killing the bacteria.This medication treats only bacterial eye infections. It will not work for other types of eye infections. Unnecessary use or misuse of any antibiotic can lead to its decreased effectiveness.