What You Should Know About Expired Contact Lenses
Just like other prescriptions, contact lens prescriptions usually expire after a year; You should have an annual eye exam to make sure your eyes remain healthy and your refractive error is unaltered. Your eye doctor can further explain why such is necessary. Never wear Expired Contact Lenses.
The contact lens expiration date is printed on the package and is usually written in mm/yy format. For example, a date of 03/18 means that the contact lens is deemed safe to use until the end of March 2018. Make sure you check before wearing it.
If you are a wearer who ignores the expiration date then here are four things you should know about the expired contact lens.
- Beyond the expiration dates, the contact lens manufacturer cannot guarantee that lenses are safe to wear. Despite that the lenses are sealed in an airtight container, it’s possible that the sealed container can become damaged and jeopardized over time, probably leading to contamination of saline solution and lens inside.
- The expiration date on the package displays the last month and year that the container should be free from contamination and the lenses inside are safe to wear.
- The doctors of the American Academy of Ophthalmology and the American Optometric Association confirmed that expired contact lenses should NOT be used. The solution containing the lenses can go bad, it can become more acidic or more alkaline and with an unstable pH (acidity) can cause infection and become uncomfortable to wear.
- Bacteria, fungi, and amoebae present on an expired contact lens can cause severe eye infections that can lead to blindness.When your prescription expires, you won’t be able to buy more lenses until you get an updated prescription, so as the date approaches you should set up an appointment with your eye doctor.
Obeying the expiration date is very important for your safety while wearing contact lenses.
A contact lens expiration date is marked on every individual lens package. Chances are high that you rarely look at that date, for a few reasons: it’s just one of a bunch of numbers on a small package, it’s not clear why it matters, and generally, the dates are so far into the future that regular wearers use all of their lenses long before the date. But while the reasons behind it might not be clear, obeying the expiration date is an important part of safely wearing contact lenses.
What the Contact Lens Expiration Date Means
The U.S. Food and Drug Administration (FDA), which regulates contact lenses and other medical devices, requires rigorous safety and efficacy testing on such products. Contact lens manufacturers are required to demonstrate, through tests, that their lenses with solution blister packs will remain stable and safe for a certain period of time, for example, perhaps five years. Essentially what it means is that the lenses, and the solution that contains them, have only been tested for that period of time, which is then used to set the expiration date to stamp on each package.
The Dangers of Expired Lenses
Beyond those expiration dates, the manufacturer cannot guarantee that the lenses are safe to wear. What can happen to the lenses after the expiration date?
The most serious concern is that poorly sealed packaging could allow bacterial and fungal contamination into the solution. These were the two things tested for in a study published in The South African Optometrist about the safety of expired lenses. In this preliminary study, the researchers did find some contamination in expired lens packs, but they were unable to make any broad claims due to very small sample size (their stated goal was more to spark further study than to answer the question authoritatively).
The Huffington Post posed the question of expired lens safety to eye doctors representing the American Academy of Ophthalmology and the American Optometric Association. The doctors confirmed that you should definitely not use expired lenses. The solution containing the lenses can go bad, they explained-specifically, it can become more acidic or more alkaline (basic). With an unstable pH (acidity), “the lens, when the solution expires, can cause infection and become very uncomfortable.”
If a contact lens has survived the long shelf life before its marked expiration date, it has probably received some abuse-perhaps from being left in the bottom of a bag or crammed into a car glovebox. This means that there is a good chance that the packaging has been compromised, allowing contamination to enter.
Bacteria, fungi, and amoebae can cause serious eye infections that can lead to blindness. That risk, however small it may be, should be enough of a reason to heed the contact lens expiration date.
Soft Contact Lens Packaging
Most soft contacts sold today are packaged individually in small, plastic “flat pack” containers with a sealed foil cover. The containers usually are filled with non-preserved buffered saline (salt water) and a wetting agent to keep the lens fully hydrated.
For cost and weight reasons, these plastic containers are much more common now than the traditional glass vials that once were the predominant packaging method for soft lenses.
The foil cover of soft contact lens containers typically displays the following information:
- Contact lens brand name
- Lens material name
- Name of manufacturer
- Base curve of lens
- Lens diameter
- Lens power
- Lot number
- Expiration date
Other information also may be included, such as the CE mark (mandatory for lenses sold in countries of the European Union and European Economic Area) and the location where the lens was made.
Gas Permeable Contact Lens Packaging
Unlike soft contact lenses, rigid gas permeable contacts generally are shipped dry from the manufacturer to the eye doctor. Also, gas permeable (GP) lenses are made-to-order and customized to the wearer’s eye shape and prescription with a lathe-cutting process.
For these reasons, there is no risk of GP lenses becoming contaminated from being kept in a fluid-filled container for long periods of time. Therefore, gas permeable contacts typically don’t require an expiration date.
The expiration date on your contact lens prescription is the last date that your eye doctor has authorized you to purchase new contacts with the prescription.
Contact lens prescriptions generally expire in one year. This is because you should have an annual eye exam if you wear contact lenses to make sure your eyes are remaining healthy and your refractive error is unchanged.