The drops put into a newborn's eyes are not vitamin K (vitamin K is an injection which newborns receive to decrease bleeding problems). The eye drops, or sometimes ointment, is used to prevent eye infections from possible exposure to bacteria in the birth canal. The most dangerous of which is gonorrhea. The most commonly used eye prophylaxis is erythromycin ointment, but some institutions use 1% silver nitrate. Because the risk of blindness is such a significant one, this use of antibiotics has become standard of care for newborns in this country, and is regulated by local health codes.