Do you have a bottle of eye drops in your medicine cabinet? How old is it? If you are not sure, you could put your eyes at risk. This is especially the case with partially used (or previously opened) bottles of eye drops. Although unopened eye drops can go bad after their expiration date, opened ones have most likely been exposed to bacteria. In either case, ophthalmologists always recommend patients to dispose of eye meds that have reached their shelf life. Here are some of the reasons why.
The longer prescription eye meds or over-the-counter drops are stored in a bottle, the more the composition of those meds change. Hence, after a given period the manufacturer of the meds cannot guarantee the effectiveness (or even the effect) of the product. In every bottle of eye medications are active and inactive ingredients. Once the product is opened, oxygen exposure can slowly begin to compromise those ingredients. In some cases, an eye solution can simply become weakened. However, at times the med becomes unstable which result in eye irritation, swelling, or redness.
Sometimes when patients use eye medications, the dropper application touches the eyeball, eyelid, or eyelashes. If this occurs, bacteria can spread from these moistened areas to the dropper. As time passes, the bacteria can overcome the bottle—especially if the solution weakens. In fact, after sometime the entire solution can be filled with bacteria. Serious consequences will occur if such a solution is applied. This is why it is a good idea to have someone else apply eye medications that are within their expiration dates.
The expiration date of eye medications is usually stamped on their packing or at the bottom of the bottle. If you cannot find it, it is best to discard the med instead of taking a chance.