Allergy eye drops are liquid medications designed to alleviate eye allergy symptoms like itching, redness, burning, and tearing. These symptoms often result from exposure to allergens such as pollen, dust, or pet dander. Like all medications, allergy eye drops have a limited lifespan and can lose effectiveness or become unsafe over time.
Understanding Eye Drop Expiration
Eye drops have two expiration considerations: the manufacturer’s printed date and the “open-bottle” period. The printed date indicates how long the product remains safe and effective when unopened and stored correctly. Unopened eye drops typically have a shelf life of one to two years from their manufacturing date.
Once opened, eye drops become susceptible to contamination and chemical changes. Multi-dose eye drops contain preservatives to inhibit bacterial, fungal, and viral growth after the seal is broken. Despite preservatives, discard multi-dose eye drops about one month (28 days) after opening, unless instructions state otherwise. Preservative-free eye drops, often packaged in single-use vials, should be used immediately and discarded within 24 hours of opening due to higher susceptibility to contamination.
Why Expired Eye Drops Are Risky
Using eye drops past their recommended discard date presents two main risks: reduced effectiveness and contamination. Over time, the active ingredients in allergy eye drops can degrade, causing them to lose potency. This means the drops may no longer effectively relieve allergy symptoms like itching or redness, leaving the condition untreated or undertreated.
The other risk is microbial contamination. Once a bottle is opened, it is exposed to the environment, and bacteria or fungi can enter. While preservatives help prevent this, their effectiveness can diminish over time. Introducing contaminated eye drops can lead to serious eye infections, causing pain, blurred vision, discharge, and even vision loss.
Maximizing Eye Drop Shelf Life
Proper storage and handling maintain eye drop integrity and prevent spoilage or contamination. Always store eye drops in a cool, dry place, away from direct sunlight and extreme temperatures. Heat and light can cause chemical ingredients to degrade, reducing their effectiveness.
Keep the cap tightly closed on multi-dose bottles to minimize exposure to air and contaminants. When applying drops, avoid touching the dropper tip to your eye, eyelid, lashes, or any other surface to prevent transferring microbes into the bottle. Sharing eye drops is not advisable, as this can spread infections. Unless instructed by the manufacturer, refrigeration is not necessary for most eye drops.
When to Discard Eye Drops
Knowing when to dispose of eye drops ensures safety and effectiveness. Always discard eye drops after the manufacturer’s printed expiration date, even if the bottle remains unopened. For opened bottles, adhere to the “open-bottle” discard period, typically one month (28 days) after initial opening for most multi-dose products. Mark the date of opening on the bottle or packaging to keep track.
Beyond these dates, eye drops should also be discarded if the solution changes color, appears cloudy, or if any visible particles are present, as these can indicate contamination or degradation. When disposing of expired or unused eye drops, return them to a pharmacy take-back program if available. If not, mix the liquid with an undesirable material like coffee grounds or kitty litter, place it in a sealed bag or container, and then dispose of it in the trash, out of reach of children and pets.