Are All Artificial Tears the Same? An Ophthalmologist’s Guide to Choosing the Right Eye Drops
Dr. Daniel Baik, Nunehim Eye Center — Guro-gu, Seoul
Quick Answer
No — artificial tears differ by ingredient and purpose: some simply add moisture (CMC, povidone), some add lubrication and protect the surface (hyaluronic acid, PEG/PG), some protect cells under dry stress (trehalose), and some are prescription treatments that actively stimulate tear and mucin production (diquafosol, rebamipide) rather than just supplementing fluid. The right choice depends less on which product is ‘strongest’ and more on what type of dry eye you actually have.
Patients working long hours on dual monitors in Gasan Digital Complex and Guro Digital Complex ask me this constantly: “Can’t I just use any artificial tears?” “What’s the difference between the pharmacy brand and what you prescribe?” “I use drops all day and I’m still dry within 10 minutes — do I need something stronger?” The short answer is that artificial tears are not interchangeable. What actually matters is not “which product is best” but “what is actually causing my dry eye.”
Q. Why isn’t dry eye just “not enough tears”?
Dry eye used to be thought of simply as a tear-volume problem. Current international guidelines (TFOS DEWS III) define it as a multifactorial disease involving loss of tear film and ocular surface homeostasis. In practice this usually breaks down into: aqueous-deficient (not enough tear production), evaporative (tears evaporate too fast, usually from meibomian gland dysfunction), mixed (both at once, very common), and cases complicated by chronic surface inflammation or corneal nerve changes. If drops keep giving only short-lived relief, the more useful move is often re-checking the underlying cause rather than switching to a “stronger” product.
Q. How do artificial tears differ by ingredient?
Hyaluronic Acid (HA / Sodium Hyaluronate)
One of the most familiar ingredients in ophthalmology. HA holds onto water and has viscoelastic properties that support lubrication and moisture retention on the eye’s surface, and it may help support epithelial recovery. In Korea, prescription HA eye drops are commonly prescribed for dry eye. Lower-viscosity formulas suit light daytime dryness; higher-viscosity formulas last longer but can cause temporary blur or stickiness.
- Good for: chronic dryness, corneal surface damage, post-LASIK/LASEK, post-cataract surgery dryness, office workers on screens all day
CMC (Carboxymethylcellulose)
Another leading artificial tear ingredient. CMC helps water stay on the eye’s surface and forms a lubricating film that reduces friction between the eyelid and cornea. Some CMC-based products are sold over-the-counter in Korea without a prescription.
- Good for: occasional dryness after computer work, afternoon eye fatigue, mild dry eye, temporary irritation
Povidone
A long-used artificial tear ingredient in Korea that supplements the tear film’s watery layer to maintain surface moisture and lubrication. Some 2% povidone products are available over-the-counter. Multi-dose bottles often contain preservatives, so anyone using drops many times a day should check for a preservative-free option.
PEG / PG (Polyethylene Glycol / Propylene Glycol)
Widely used internationally, PEG/PG-based drops form a lubricating, protective film that reduces friction and dryness. Depending on the formulation, they can form a gel or linger longer on the tear film, which often suits patients who feel dry again “just minutes” after using regular drops. Formulations vary significantly between brands, so check viscosity and preservative content, not just the active ingredient.
Trehalose
An increasingly common ingredient in newer artificial tears. Beyond basic moisturizing, trehalose has been studied for protecting ocular surface cells under dry, hyperosmolar stress conditions — a property highlighted in the TFOS reports. It’s often considered for people exposed to air-conditioning or heating all day, long hours on screens, or afternoon stinging/burning that worsens with dry environments. Some combination formulas pair trehalose with hyaluronic acid.
Don’t Forget the Lipid Layer
This is the part patients most often miss. Tears aren’t just water — the outer lipid layer, produced by the Meibomian glands in the eyelids, keeps that water from evaporating too fast. When Meibomian Gland Dysfunction (MGD) is present, tears evaporate quickly even if volume is adequate, producing the classic pattern of “drops feel great for a moment, then I’m dry again in 5–10 minutes.” In these cases, a lipid-supporting formula can help more than a purely aqueous one — but moderate-to-severe MGD often needs more than drops alone. Current TFOS DEWS III guidance lists warm compresses, eyelid hygiene, and where appropriate, in-office treatments including IPL as options alongside artificial tears.
Diquafosol: More Than Just a Lubricant
Diquafosol isn’t simply a lubricating drop — it’s a prescription dry eye treatment that acts on P2Y2 receptors on the conjunctiva to stimulate both water and mucin secretion. It requires a doctor’s prescription in Korea. Both 3% and some 5% formulations exist, and dosing frequency varies by product, so follow your prescribed regimen. Approved indications in Korea relate to improving corneal and conjunctival epithelial disorders associated with dry eye.
- Consider when: regular artificial tears give only short relief, tear film instability is significant, corneal/conjunctival epithelial damage is present, or mucin layer dysfunction is suspected
Rebamipide: Originally a Stomach Drug, Now an Eye Treatment
Rebamipide is well known as a gastric mucosal protectant, but on the eye’s surface it has been studied for increasing mucin production and secretion and improving corneal and conjunctival epithelial status. A 2% rebamipide eye drop is approved as a prescription treatment in Korea for improving corneal and conjunctival epithelial disorders associated with dry eye in adults. Diquafosol and rebamipide are best understood not as “moisturizing drops” but as prescription treatments targeting specific dry eye mechanisms.
Artificial Tears at a Glance
| Ingredient | Main Role | OTC / Prescription | Often Suits |
|---|---|---|---|
| Hyaluronic Acid (HA) | Lubrication, moisture, surface protection | Mostly prescription in Korea | Chronic dryness, post-surgery, epithelial damage |
| CMC | Moisture retention, friction reduction | Some OTC | Mild dryness, office eye fatigue |
| Povidone | Aqueous layer support, lubrication | Some OTC (2%) | Mild dryness |
| PEG / PG | Lubricating/protective film | Varies by product | Frequent dryness, needs longer-lasting relief |
| Trehalose | Moisture + cell protection under dry stress | Varies by product | AC/heating exposure, long screen time |
| Diquafosol | Stimulates tear & mucin secretion | Prescription only | Unstable tear film, moderate-to-severe dry eye |
| Rebamipide | Boosts mucin, improves epithelium | Prescription only | Corneal/conjunctival epithelial disorders |
Q. What’s actually different between pharmacy and prescription eye drops?
Over-the-counter products are generally lubricating/moisturizing formulas — CMC, povidone, and similar ingredients — meant to relieve temporary dryness or mild irritation without needing a diagnosis first. They’re convenient but may not be enough when the real driver is evaporative dry eye, MGD, epithelial damage, or inflammation.
At an eye clinic, treatment isn’t chosen from symptoms alone. After slit-lamp exam, tear breakup time testing, corneal/conjunctival staining, and eyelid/meibomian gland assessment, we can select from HA-based drops, diquafosol, rebamipide, anti-inflammatory treatment, or other ocular surface therapies as appropriate. The real difference between OTC and prescription isn’t “stronger vs. weaker” — it’s that prescription treatment is matched to your diagnosed cause and mechanism.
Q. Why do preservatives matter as much as the ingredient?
If you use artificial tears frequently, preservatives matter just as much as the active ingredient. Multi-dose bottles often contain a preservative — commonly benzalkonium chloride (BAK) — to prevent contamination after opening. Used appropriately it’s usually fine, but repeated long-term exposure can be associated with surface irritation in sensitive eyes or very frequent users.
Preservative-free products are generally worth prioritizing if you: use drops many times a day, have significant dry eye or corneal epithelial damage, are recovering from LASIK/LASEK, use multiple eye medications together, wear contact lenses, or are simply sensitive to preservatives. “More than 4 times a day = automatically preservative-free” is a useful rule of thumb, not an absolute rule — the higher your frequency of use, the more reasonable it is to consider preservative-free options.
Q. So which artificial tears should you actually choose?
- Occasional dryness after computer work → lubricating types like CMC, povidone, or PEG/PG
- Dry all day and need frequent drops → prioritize preservative-free formulas
- Eyes sting the moment the AC turns on → moisture + surface protection types like trehalose or HA
- Dry again within 10 minutes of using drops → check for evaporative dry eye / MGD first
- Dry, oily, or crusted eyelid margins first thing in the morning → check meibomian gland status before choosing a drop
- Recurring corneal damage or post-surgical eyes → preservative-free prescription drops via an eye exam
- Regular drops aren’t working anymore → evaluate for diquafosol, rebamipide, or anti-inflammatory treatment
From Dr. Daniel Baik
“Patients often carry two or three different artificial tears in their bag. What I actually want to know isn’t which one they’re using — it’s why they need one so often. If regular drops only last a few minutes, that’s not a signal to buy a stronger bottle. It’s a signal to find out what’s really going on with your tear film.”
❓ Frequently Asked Questions
Q. Is the most expensive artificial tear the best one?
No. Price matters far less than whether the ingredient matches your type of dry eye. A patient with aqueous-deficient dry eye and a patient with severe evaporative MGD will not do equally well on the same product.
Q. Can I reuse a single-use eye drop vial later in the day?
If the product is labeled for single use, the leftover solution and container should not be reused once opened — this is standard guidance for preservative-free single-dose vials, including single-dose diquafosol products sold in Korea.
Q. Can I use artificial tears while wearing contact lenses?
Not all products are contact-lens compatible — check the label specifically, since some preserved drops require lens removal first depending on lens material. When in doubt, ask your ophthalmologist or pharmacist.
Q. My eyes feel better right after using drops, but dry again within minutes — why?
This is one of the most common patterns I see, and the first thing I check for is Meibomian Gland Dysfunction (MGD). When the oil layer is insufficient, tears evaporate quickly no matter how much moisture you add. In these cases, warm compresses, eyelid hygiene, and — depending on severity — meibomian gland treatment or M22 IPL may be considered alongside drops.
Q. Should artificial tears be refrigerated?
Most products are meant to be stored at room temperature per their labeling; refrigeration isn’t automatically better and some products (including certain diquafosol formulations sold in Korea) are approved for room-temperature storage between roughly 1–30°C. Always follow the specific product’s storage instructions.
Q. Is a higher hyaluronic acid concentration always better?
No. Higher concentration can mean longer-lasting lubrication, but also more viscosity, which can cause temporary blurring or a sticky sensation right after application. Some patients use a lighter formula during the day and a thicker one at night.
Q. What kind of artificial tears are best after LASIK or TransPRK?
Preservative-free drops are commonly used during the corneal healing period after refractive surgery, since the nerves and ocular surface are more sensitive. The exact product and frequency depends on your procedure and how your eyes are healing, so follow your surgeon’s specific instructions.
Q. Does constantly using artificial tears make your eyes ‘lazy’ and produce less tears?
There’s no evidence that routine lubricating drops cause dependency or reduce natural tear production. In fact, needing drops very frequently is often a sign that the underlying dry eye isn’t adequately treated yet — not a sign the drops themselves are the problem.
Book a Consultation
Not sure which artificial tears actually fit your dry eye? Get a full dry eye evaluation at Nunehim Eye Center in Guro-gu, Seoul.
Or visit nunehim.com
📍 Visit Nunehim Eye Center — Guro, Seoul
Convenient access from Guro, Gasan, Gwanak & Yeongdeungpo. Near Guro Digital Complex Station (Line 2).
Address
551 Siheung-daero, Guro-gu, Seoul · nunehim.com
Hours
Mon–Fri 09:00–18:30 (lunch 13:00–14:00), Sat 09:00–14:00
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