What are the side effects of hyaluronic acid eye drops?

October 8, 2025 •

4 min read

An estimated 6.8% of the adult population in the United States, or over 16 million people, have been diagnosed with dry eye disease [1.8.2]. For many, hyaluronic acid (HA) eye drops are a primary treatment, but it's important to understand the question: what are the side effects of hyaluronic acid eye drops?

Quick Summary

Hyaluronic acid eye drops are generally safe, with the most common side effects being temporary blurred vision and mild stinging upon application. Severe reactions are rare but can include signs of an allergic reaction.

Key Points

Generally Safe: Hyaluronic acid (HA) eye drops are considered safe for long-term use with a low risk of adverse events [1.4.1, 1.4.6].
Common Side Effects: The most common side effects are temporary blurred vision and mild, short-lived stinging or irritation upon application [1.2.1, 1.2.2].
Rare Allergic Reactions: While HA is a natural substance in the body, rare allergic reactions can occur, potentially due to other ingredients. Symptoms include severe itching, swelling, or difficulty breathing [1.5.1, 1.5.3].
Preservative-Free is Gentler: Preservatives in multi-dose bottles can cause irritation. Preservative-free (PF) options are recommended for sensitive eyes or frequent use (more than 4x daily) [1.7.3, 1.7.4].
Concentration Matters: Higher concentrations of HA (e.g., 0.3%-0.4%) may offer longer relief but are also more likely to cause temporary blurred vision [1.3.1].
Promotes Healing: Beyond lubrication, HA has been shown to promote the healing of the corneal surface by aiding in epithelial cell migration [1.3.2, 1.9.1].
When to See a Doctor: Consult a doctor if you experience persistent pain, significant changes in vision, or signs of a serious allergic reaction after using the drops [1.2.5].

Understanding Hyaluronic Acid in Ocular Health

Hyaluronic acid, also known as hyaluronan or sodium hyaluronate, is a glycosaminoglycan—a naturally occurring polysaccharide found throughout the human body, especially in connective tissues, skin, joints, and the vitreous of the eye [1.3.2, 1.4.1]. Its primary function is to bind and retain water; it can hold up to 1,000 times its weight in water, making it an exceptional lubricating and hydrating agent [1.9.2, 1.9.5]. In ophthalmology, this property is harnessed in artificial tears to treat dry eye disease (DED) [1.9.3]. When used in eye drops, HA works by thickening and stabilizing the tear film, reducing friction between the eyelid and cornea during blinking, and promoting the healing of the corneal epithelium [1.9.1, 1.9.2].

How Hyaluronic Acid Eye Drops Work

HA's effectiveness in eye drops stems from several key characteristics [1.9.1, 1.9.2]:

Hydration: Its ability to attract and retain a high volume of water helps to re-wet the ocular surface and slow the evaporation of tears.
Viscoelasticity: This property allows the tear film to better withstand the shearing stress of blinking, providing a stable, protective layer that reduces mechanical irritation.
Wound Healing: Studies have demonstrated that HA aids in the migration and proliferation of corneal epithelial cells, which is crucial for repairing minor surface damage caused by dryness [1.3.2, 1.9.5].
Biocompatibility: Since HA is a natural component of the eye, it is generally well-tolerated with a low risk of adverse reactions [1.4.6].

What are the Side Effects of Hyaluronic Acid Eye Drops?

While considered safe for long-term use, some individuals may experience side effects [1.2.4, 1.4.6]. These are typically mild and transient.

Common and Mild Side Effects

The most frequently reported side effects occur immediately after instillation and resolve quickly:

Blurred Vision: A temporary blurring of vision is common, especially with higher concentration (more viscous) drops [1.2.2, 1.3.1]. Blinking a few times usually helps spread the drop and clear the vision [1.2.1].
Mild Stinging or Burning: A brief stinging or burning sensation upon application can occur [1.2.1, 1.4.2]. This discomfort typically passes within a few minutes [1.3.6].
Eye Irritation or Redness: Some users may experience temporary redness or general irritation [1.3.1, 1.4.2].
Foreign Body Sensation: A feeling that something is in the eye can occur shortly after using the drops [1.2.1].

Rare but More Serious Side Effects

Though uncommon, more significant side effects require medical attention. Allergic reactions to sodium hyaluronate itself are minimal since it's a substance natural to the body, but other ingredients or the formulation can cause issues [1.3.5, 1.5.3].

Signs of a potential serious reaction include [1.2.5, 1.5.1]:

Persistent or worsening eye pain
Significant changes in eyesight
Symptoms of an allergic reaction, such as:
- Itching or hives
- Swelling of the mouth, face, lips, tongue, or throat
- Wheezing or tightness in the chest
- Trouble breathing or swallowing

If any of these severe symptoms occur, use of the product should be stopped, and a healthcare professional should be consulted immediately [1.3.5].

Factors Influencing Side Effects

Preservatives vs. Preservative-Free

Many artificial tears contain preservatives, like benzalkonium chloride (BAK), to prevent bacterial growth in the bottle [1.7.4]. However, these preservatives can cause irritation, stinging, and even damage the ocular surface, especially with frequent, long-term use [1.7.4, 1.7.5]. For individuals with moderate to severe DED or those who use drops more than four times a day, preservative-free (PF) formulations are often recommended [1.4.2, 1.7.3]. PF drops come in single-use vials and are much gentler on the eye, reducing the risk of preservative-induced side effects [1.7.1].

Concentration and Molecular Weight

HA eye drops are available in various concentrations, typically ranging from 0.1% to 0.4% [1.3.1, 1.3.3]. Higher concentrations are more viscous, which may provide longer-lasting relief but can also increase the likelihood of temporary blurred vision [1.3.1, 1.9.1]. Additionally, the molecular weight (MW) of the HA can influence its effects. High molecular weight HA has been shown to have better anti-inflammatory and lubricating properties compared to low molecular weight HA [1.9.1, 1.9.3].

Comparison Table: Hyaluronic Acid vs. Other Lubricants


Feature	Hyaluronic Acid (HA)	Carboxymethylcellulose (CMC)	Hydroxypropyl Guar (HPG)
Mechanism	Binds water, viscoelastic, promotes healing [1.9.1, 1.9.2]	Increases tear retention time, bioadhesive [1.6.1]	Forms a gel-like matrix on the eye surface to stabilize tears [1.6.5]
Natural to Body	Yes, found in the eye's vitreous humor [1.3.2]	No, it is a cellulose derivative [1.6.1]	No, it is a plant-derived polymer
Efficacy	Very effective, especially for moderate-to-severe DED. Tends to show more rapid symptom reduction than CMC [1.6.3, 1.6.6].	Equally effective as HA in some studies for mild-to-moderate DED, but may have slower onset of symptom relief [1.6.3, 1.6.4].	Often combined with HA; one study showed HPG/HA drops led to faster corneal wound recovery than CMC/HA drops [1.6.5].
Common Side Effect	Temporary blurred vision, mild stinging [1.2.2]	Similar mild irritation [1.6.3]	Ocular hypertension was reported in one case, but deemed unrelated to treatment [1.6.5].

Conclusion

Hyaluronic acid eye drops are a highly effective and safe treatment for the symptoms of dry eye disease, with a low incidence of side effects. The most common issues are minor and temporary, such as blurred vision and slight stinging. The risk of irritation can be further minimized by choosing preservative-free formulations, especially for those with sensitive eyes or a need for frequent application. While rare, signs of an allergic reaction or persistent pain warrant immediate medical consultation. Overall, the benefits of hydration, lubrication, and corneal healing make HA drops a cornerstone of modern dry eye management [1.4.6].

For more information from an authoritative source, you can visit the National Eye Institute: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye

Frequently Asked Questions

Yes, hyaluronic acid eye drops are considered safe for long-term use. Clinical studies have shown they are well-tolerated with no major complications reported even with use up to 3 months, and they can be used for extended periods if required [1.2.1, 1.4.6].

The most common side effects are temporary and mild, including blurred vision immediately after application, a slight stinging or burning sensation, and minor eye irritation [1.2.1, 1.2.2, 1.4.2].

While rare, allergic reactions can occur. Symptoms include itching, hives, swelling of the face or throat, and trouble breathing. If you experience these, stop using the drops and seek medical help immediately [1.5.1].

The frequency depends on the severity of your dry eye and the product's formulation. Some people use them 3-4 times a day, but they can be used as often as needed. If you use them more than 10 times a day or if they contain preservatives, it's best to consult your eye doctor [1.2.4, 1.4.4].

Preservative-free eye drops are often better for individuals with sensitive eyes, those who wear contact lenses, or anyone who needs to apply drops more than four times a day. Preservatives like benzalkonium chloride (BAK) can cause irritation with frequent use [1.7.1, 1.7.4].

Generally, yes, especially if you use preservative-free versions. However, preservatives in some bottles can accumulate on soft contact lenses [1.2.4]. It is recommended to wait about 30 minutes after inserting contacts before using some types of drops, or check with your doctor [1.4.4].

Higher concentration drops (e.g., 0.3% vs 0.1%) are more viscous (thicker) and may provide longer-lasting relief, but they are also more likely to cause temporary blurred vision right after use [1.3.1, 1.3.5].