Eye drops are saline solutions with the addition of drugs. Some eye drops reduce redness or lubricate the eyes to relieve dryness, while others relieve itching caused by allergies.
There are no universal eye drops, just as there is no universal expiration date. Generally, the expiration date is given about one to two years after the date of manufacture, but even the Food and Drug Administration says the number can be arbitrary.
Each type of eye drop has a unique expiration date and the ingredients can affect this expiration date.
For example, in Clear Eyes Redness Relief eye drops, the active chemicals glycerin (lubricant) and naphazoline HCl (anti-redness agent) are eventually broken down, meaning they are less effective and safer.
Over time, these chemicals can break down into potentially dangerous compounds, says Jacqueline Haugsdal, MD, a vision and eye care specialist at the University of Iowa Hospital and Clinics.
In addition, many eye drops contain preservatives that help them last longer and prevent bacterial contamination. According to the American Academy of Ophthalmology (AAO), most eye drops containing preservatives have a shelf life of at least one year after manufacture.
It is usually safe and effective to use these eye drops before their expiration date. However, the AAO says that if you open eye drops, they probably have a much shorter expiration date and you should throw them away three months after opening – even before they expire.
This is because once the eye drops are opened, exposure to oxygen will accelerate the decomposition of the chemical components, making the liquid medicine weaker.
Unpreserved eye drops (usually in disposable vials) should be discarded within 24 hours of opening. They are usually disposable.
Vivian Shibayama, OD, an eye and vision care specialist at UCLA Health, said expiration dates indicate that the effectiveness or sterility of the eye drops is no longer guaranteed.
Because the preservatives that keep eye drops sterile weaken over time, bacteria can contaminate the bottle once opened and cause an eye infection, she said.
Chemical degradation of other materials can also cause eye irritation. Other risks of using expired eye drops include redness and blurred vision due to irritation from decaying chemicals, Haugsdal says, so she doesn’t recommend using expired eye drops.
Do not leave eye drops in a car, pocket, or in direct sunlight, as heat and bright light can destroy the compounds in the medicine. A good way to determine if eye drops are not working is to see if they are cloudy or otherwise change color.
Post time: Feb-15-2023