“Most patients reported using 10 different brands of artificial tears, but EzriCare Artificial Tears, “a preservative-free” brand. Notice preservative free, I’m guessing a preservative would have killed the bacteria.”
The eyedrop solution is supposed to be sterile when purchased so someone screwed up the sterilization cycle on the solution or the contamination was in the bottles which are also supposed to be sterile. The preservative (usually benzalkonium chloride) is there to prevent bacterial growth after the bottle is opened and is more of a disinfectant.
Sounds like solid information.