How long can you use your eye drop after opening?
Eye drops should be used and maintained properly to remain safe and effective until the expiration date, unless otherwise stated in the box insert. The risk of infection is higher once your eye drops are opened, therefore you should discard them after three months of use.
There is a risk of contamination once the bottle's sterile seal has been compromised, particularly if the bottle's tip touches your eye or any other surface. The majority of eye drops have preservatives in them to prevent infection from bacteria, viruses, and fungus as well as to restrict their growth.
Regardless of when the drug was opened, these preservatives should guard against contamination at least until the expiration date of the medication.