QUOTE(iSean @ Dec 30 2011, 10:11 AM)
I justed used Eye Glo Plus Conforts Strained & Tired Eyes, Eye drops, then I notice it's been expired like 4 months ago at 08/2011... And someone wrote 24/2/09 maybe the date when it was bought... Opened...
If it's expired only 4 months, don't worry about it. I would stop using it. But I wouldn't worry about having already used it a few times.
The way expiry dates for anything is set, on one side of the expiry date, you can be reasonably sure that the material is still good and useable. But on the other side of the expiry date, you cannot be sure that the material would be spoilt and unusable. In fact, it is frequently still useable. It's just that you can no longer be sure it is.
Nobody can predict the exact date of spoilage. And spoilage takes place over a period of time. It's not like the eye drop is perfect good at a moment in time, and one minute later, as the clock strikes midnight, it turns completely harmful.
I would be more concern about the note that it was opened nearly 3 years ago.
QUOTE
I only have 1 sets of eyes... I just rinsed them under water... What will the worst thing could happen to my eyes if used.
You assume the water is harmless and contains fewer microorganisms than what is in the bottle. This may not be true.

Watch out for any symptoms. If they develop, go visit a doctor. Otherwise, don't worry about it. Worry makes you unhealthy. It's definitely too early to make an appointment with an optometrist. Yes you only have one set of eyes. But just apply common sense.