Applying eye drops can sometimes cause an uncomfortable burning sensation. This common experience often raises questions about its cause and whether it signals a problem. Understanding the various factors that contribute to this temporary discomfort can help demystify the sensation. This article explores the reasons why eye drops might burn, explaining when the burning is typical and when it might warrant further attention.
Common Reasons for Temporary Burning
A frequent cause of temporary burning relates to preservatives in many eye drop formulations. Chemicals like benzalkonium chloride (BAK) prevent bacterial growth but can irritate the eye’s surface. This irritation is noticeable with frequent use or in sensitive eyes, as BAK can disrupt the natural tear film and damage ocular surface cells over time. Preservatives act as detergents on the eye, and their effects can be cumulative, leading to discomfort and inflammation.
The pH balance of eye drops also plays a significant role. The eye’s natural tear film maintains a specific pH, typically around 7.4. If an eye drop’s pH deviates considerably from this level, whether too acidic or too alkaline, it can cause temporary stinging or burning as the eye adjusts. Some medicated eye drops, like those for glaucoma, may have pH levels outside the eye’s natural range for stability or efficacy.
Certain active ingredients in medicated eye drops can induce mild irritation. For instance, nonsteroidal anti-inflammatory drugs (NSAIDs) in some eye drops can cause stinging or burning. Similarly, ingredients in redness-reducing drops, like vasoconstrictors (e.g., naphazoline or tetrahydrozoline), constrict blood vessels but can also lead to temporary irritation.
The osmolarity (concentration of solutes) in eye drops compared to natural tears can also contribute to burning. If an eye drop is significantly hypertonic (more concentrated) or hypotonic (less concentrated) than the tear film, it can cause a temporary osmotic imbalance and burning.
When Burning Signals a Problem
While some burning is temporary and expected, persistent or severe burning can indicate an underlying issue or adverse reaction. An allergic reaction to specific ingredients can manifest as more than burning. Symptoms may include severe itching, noticeable swelling of the eyelids, and persistent redness. These reactions can occur due to sensitivity to active ingredients, preservatives, or other additives.
Existing eye conditions can make the ocular surface vulnerable, causing even mild eye drops to burn intensely. For example, individuals with severe dry eye may experience heightened sensitivity, as their tear film is already compromised. Conditions like corneal abrasions, infections (e.g., conjunctivitis), or general inflammation can also leave the eye’s surface more exposed and reactive to foreign substances. In these cases, the burning is often exacerbated by the pre-existing condition.
Contaminated eye drops pose a risk of irritation or infection, leading to burning. This can happen if the dropper tip touches the eye or any other surface, introducing bacteria. Additionally, using expired or improperly stored eye drops may result in ingredient breakdown or microbial growth, making them irritating or unsafe. Dispose of drops if the seal is broken or if they appear tainted.
Applying the wrong type of eye drop can also worsen symptoms, including burning. For instance, using redness-relief drops containing vasoconstrictors for chronic dry eye can lead to a rebound effect, where redness returns more intensely and dryness exacerbates. These drops do not address the root cause of dryness and can create further irritation.
Practical Steps for Relief
To minimize burning, preservative-free artificial tears are often recommended, especially for frequent use or sensitive eyes. Preservative-free options, found in single-use vials or specialized multi-dose bottles, reduce the risk of irritation and inflammation caused by chemicals like BAK. These formulations are gentler on the ocular surface and are particularly beneficial for those with dry eye.
Proper application technique can reduce discomfort. Wash hands before handling eye drops and avoid touching the dropper tip to the eye or any surface to prevent contamination. After instilling a single drop, gently close the eye for two to three minutes and apply light pressure to the inner corner of the eyelid. This helps ensure absorption and prevents the drop from draining too quickly. Avoiding excessive blinking after application also helps the drop spread evenly.
If burning is severe, persistent, or accompanied by pain, vision changes, or unusual discharge, consult an eye care professional. Such symptoms could indicate an underlying eye condition, an allergic reaction, or an infection requiring medical diagnosis and treatment. A healthcare provider can assess the situation, determine the cause, and recommend appropriate alternatives or treatments.
Reviewing eye drop ingredient lists can be helpful, especially if a pattern of burning is observed with specific types of drops. If a particular ingredient, such as BAK or certain active components, consistently causes irritation, seek alternatives without that ingredient. Discussing ingredient sensitivities with an eye care professional can guide the selection of more compatible eye drop formulations.