Eyedrops can cause a burning sensation upon application. While often a normal, brief response, this reaction can also indicate underlying issues with the eyedrops or your eyes. Understanding these reasons helps determine if the discomfort is temporary or a signal to seek professional advice.
Ingredients and pH Levels
The chemical composition of eyedrops is a primary factor influencing burning sensations. Many eyedrops contain preservatives, such as benzalkonium chloride (BAK), added to prevent contamination and extend shelf life. These preservatives, especially BAK, can irritate the delicate surface of the eye, leading to stinging or burning. BAK can disrupt the tear film and damage eye cells, causing discomfort and worsening dry eye symptoms with long-term use.
The pH level of eyedrops also plays a significant role. Natural human tears typically have a pH balance around 6.5 to 7.6. If an eyedrop’s pH deviates significantly from this natural range, it can cause discomfort and burning upon contact with the eye’s sensitive surface. Some medicinal eyedrops, especially prescription ones, may have a pH outside this ideal range to maintain the stability and effectiveness of their active ingredients. For sensitive eyes, preservative-free eyedrops are available and designed to be gentler, reducing irritation and burning.
Existing Eye Conditions
Existing eye conditions can influence how eyes react to eyedrops. Eyes compromised by certain conditions may be more sensitive and prone to burning, even from drops typically well-tolerated by healthy eyes. For instance, dry eye syndrome often involves an unstable tear film or microscopic abrasions, making eyes more susceptible to irritation from eyedrop ingredients. Insufficient natural tears diminish the eye’s protective barrier.
Conditions like corneal abrasions (scratches on the eye’s surface) can cause severe pain. When eyedrops are applied to an abraded cornea, exposed nerve endings react intensely, causing significant burning. Similarly, inflammation or infections like conjunctivitis or blepharitis can make eyes hypersensitive. In these instances, the eye’s irritated surface reacts more strongly to eyedrop ingredients, exacerbating discomfort.
Allergic Responses
Beyond general irritation, a burning sensation from eyedrops can signal an allergic reaction. An allergic response involves the immune system overreacting to specific eyedrop components, including active medications or preservatives. While some discomfort is expected, an allergic reaction typically involves additional symptoms beyond burning, such as itching, redness, swelling of the eyelids, or watery discharge.
The immune system identifies an ingredient as an allergen, triggering a response that releases chemicals like histamine, which cause the characteristic symptoms. This reaction can worsen with repeated exposure to the eyedrop. For example, benzalkonium chloride (BAK), a common preservative, has been implicated in allergic reactions. Distinguishing between irritation and an allergic reaction is important, as an allergy requires identifying and avoiding the specific trigger.
When to Seek Medical Advice
While a mild, temporary burning sensation from eyedrops can be normal, certain symptoms warrant medical attention from an eye care professional. You should seek advice if the burning is severe, persistent, or worsens over time. Accompanying symptoms like significant eye pain, increased redness, swelling, or discharge are red flags that could indicate an infection, an allergic reaction, or another underlying eye condition.
Changes in vision, such as new blurriness or light sensitivity, especially after starting a new eyedrop, also necessitate professional evaluation. If you experience hives, wheezing, or difficulty breathing, these could be signs of a severe allergic reaction requiring emergency medical care. It is always advisable to consult an eye doctor if you are concerned about your symptoms, or if over-the-counter drops are not providing relief.