Each Restasis vial is designed to be used exactly once. You open it, put a drop in one or both eyes, and throw it away immediately, even though liquid remains in the vial. The manufacturer, the FDA label, and ophthalmology guidelines all agree: do not save an opened vial for later, even if you refrigerate it.
Why There’s Only One Use Per Vial
Restasis is preservative-free. That’s actually a benefit for your eyes, since preservatives in eye drops can irritate sensitive or dry eyes over time. But it also means that once you twist open a vial, nothing inside is fighting off bacteria, viruses, or fungi that may enter the liquid.
Each vial holds 0.4 mL of fluid. A single eye drop is roughly 0.028 mL, so the vial technically contains enough liquid for about 14 drops. That math is exactly why so many people wonder if they can get a second or third use out of one vial. But the extra volume exists to make it easier to squeeze the drop out, not to provide multiple doses. The official Restasis FAQ addresses this directly: even storing an opened vial in the refrigerator does not make it safe for a second use.
What Happens If You Reuse a Vial
The moment a vial is opened, airborne microbes can settle into the liquid. If the vial tip touches your eye, eyelid, or fingers, bacteria from your skin transfer into the solution. Without a preservative to kill those organisms, they can multiply freely inside the warm, moist environment of the vial.
Research published in Translational Vision Science & Technology found that contaminated eye drop containers can harbor harmful bacteria including MRSA and Pseudomonas aeruginosa. Pseudomonas is particularly dangerous for the eye. When introduced to the cornea, it can cause aggressive infections that in severe cases lead to removal of the eye. Other pathogens commonly found in contaminated eye solutions include skin flora bacteria and adenoviruses, which can survive on surfaces for three to eight weeks at room temperature.
Preserved eye drops carry some built-in protection against this kind of contamination. Restasis has none, which is why the single-use rule is stricter here than for many other eye drops.
Using One Vial for Both Eyes
You can use the same vial for both eyes during a single sitting. The FDA label says each vial is “for administration to one or both eyes,” with the remaining contents discarded immediately after. So if your doctor has prescribed Restasis for both eyes, open one vial, put a drop in each eye, and discard the vial. You do not need two vials per dose.
The key word is “immediately.” Both drops should happen back to back. Setting the vial aside on your bathroom counter for a few hours and coming back to it later is what creates contamination risk.
The Multidose Bottle Option
If the waste from single-use vials bothers you, there is an alternative. A multidose version of Restasis uses the same preservative-free formula but comes in a bottle with a one-way valve and air filter designed to prevent bacteria from entering after each use. This lets you get multiple doses from the same container without the contamination risk of a simple open vial. It contains the same active ingredient at the same concentration. Ask your prescriber or pharmacist whether the multidose version is available and covered by your insurance.
How to Handle Unopened Vials
Restasis typically comes in foil pouches containing several single-use vials. Unopened vials stored in their original pouch remain sterile and can be kept at room temperature. Once you pull vials out of the pouch, they should be used within a reasonable timeframe, though they don’t need refrigeration before opening. The important distinction is between an unopened vial (sterile, safe to store) and an opened one (use immediately, then discard).
Restasis is prescribed as one drop in each affected eye, twice a day, roughly 12 hours apart. That means you’ll go through two vials per day if treating both eyes. A standard 30-day supply contains 60 vials. The cost and waste can feel significant, which is a common reason people look for ways to stretch each vial further. But given the infection risks of reusing a preservative-free container, the single-use design is a safety measure worth following.