Most Refresh eye drops can be used as often as needed, but there’s an important distinction: if your Refresh product contains a preservative, you should limit use to four times a day or fewer. Preservative-free versions have no strict daily cap. Which type you’re using determines how freely you can reach for the bottle.
The Four-Times-a-Day Rule for Preserved Drops
Most multi-dose bottles of artificial tears, including several Refresh products, contain preservatives to prevent bacterial growth once the bottle is opened. The general guideline from eye care professionals is to use preserved drops no more than four times per day. Beyond that threshold, the preservative itself starts to cause problems. It can irritate the surface of your eye, trigger inflammation, and actually make dryness and redness worse over time.
The preservative most commonly linked to these issues is benzalkonium chloride, or BAK. Research shows it damages corneal surface cells, promotes inflammation, and can even affect the tiny nerve fibers in the cornea. The effect is cumulative: occasional exposure is well tolerated, but repeated daily exposure above four doses starts to overwhelm the eye’s ability to recover between drops. Some Refresh products use a gentler preservative called Purite, which breaks down into natural tear components on contact with the eye. It’s considered less toxic than BAK, but the four-dose guideline is still a reasonable ceiling for any preserved formula.
Preservative-Free Drops Have No Fixed Limit
Refresh sells several preservative-free options, including Refresh Digital Preservative-Free and Refresh Relieva PF. These come in single-use vials rather than multi-dose bottles, and their label directions simply say to instill one or two drops “as needed.” There’s no upper limit printed on the packaging because, without a preservative in the formula, there’s no chemical building up on your eye with each dose.
In practice, some people use preservative-free drops six, eight, or even more times a day without issue. After LASIK surgery, for example, ophthalmologists at Walter Reed National Military Medical Center instruct patients to use preservative-free Refresh Plus at least once every hour during waking hours, a pace that works out to roughly 15 or 16 doses a day. That frequency continues beyond the first day of recovery. If your eyes are that dry, preservative-free drops can safely keep up with the demand.
That said, if you find yourself reaching for drops more than four or five times daily on a regular basis, it’s worth figuring out why. Frequent artificial tear use can mask an underlying condition like meibomian gland dysfunction, allergic eye disease, or medication side effects that would benefit from targeted treatment rather than constant lubrication.
How to Tell Which Type You Have
The easiest way to check is the packaging. Preservative-free Refresh products are clearly labeled “Preservative-Free” or “PF” on the box and come in individual single-use vials. Multi-dose bottles that you recap and reuse almost always contain a preservative, whether it’s BAK, Purite, or another agent. If you’re unsure, look at the inactive ingredients list on the label or the Drug Facts panel.
Here’s a quick breakdown of some common Refresh products:
- Refresh Tears (multi-dose bottle): Contains Purite preservative. Stick to four times a day or less.
- Refresh Relieva PF (single-use vials): Preservative-free. Use as often as needed.
- Refresh Digital Preservative-Free (single-use vials): Preservative-free. Use as often as needed.
- Refresh Relieva for Contacts: Labeled “safe to use as often as needed.” Can be applied with soft or rigid gas permeable lenses in place.
Signs You’re Using Drops Too Often
If you’re using a preserved formula more than four times a day, watch for increasing redness, a stinging or burning sensation that wasn’t there before, or eyes that feel drier shortly after each drop. These are classic signs of preservative toxicity on the corneal surface. The fix is straightforward: switch to a preservative-free version, which removes the irritant entirely.
Even with preservative-free drops, consistently needing them every hour or two for weeks on end suggests something beyond simple environmental dryness. Screen time, ceiling fans, certain medications (antihistamines, antidepressants, blood pressure drugs), and autoimmune conditions can all drive chronic dry eye that benefits from more than artificial tears alone.
Tips for Getting the Most From Each Drop
Tilt your head back slightly, pull down your lower eyelid to form a small pocket, and place one drop into that pocket. Close your eye gently for 30 seconds rather than blinking rapidly, which pushes the drop out through your tear ducts before it can coat the surface. One drop is usually enough per eye. Two is fine if the first didn’t land well, but more than that just overflows and runs down your cheek.
If you use preservative-free single-use vials, you can recap a vial and reuse it within the same day, though most manufacturers recommend discarding it after a single use to avoid contamination. Never touch the tip of any dropper to your eye or eyelashes, as this introduces bacteria into the solution. And if you use multiple types of eye drops (for allergies or glaucoma, for instance), wait at least five minutes between each one so the first drop has time to absorb.