Eye drops are a common solution for various eye conditions, from dryness and allergies to infections. Many experience a temporary stinging or burning sensation after applying them. While often normal and brief, this sensation can sometimes indicate an underlying issue with the eye drops or the eye itself. Understanding the reasons helps determine when it is a typical reaction and when it might be a cause for concern.
Understanding Why Eyedrops Can Sting
A temporary stinging or burning sensation from eyedrops can arise from several physiological factors. The eye’s natural tear film maintains a delicate balance, with a pH around 7.0 to 7.6 and an osmolarity of about 300 mOsm/L. If eyedrops have a significantly different pH or salt concentration (osmolarity) compared to tears, it can cause transient stinging as the eye adjusts.
Many eyedrops contain preservatives to prevent bacterial growth and extend shelf life. Benzalkonium chloride (BAK) is a common preservative known to cause irritation or stinging, especially with frequent use or in sensitive eyes. Long-term exposure to BAK can even damage the ocular surface. Some active medicinal ingredients, such as those in glaucoma or allergy drops, can inherently cause a burning sensation as part of their mechanism of action. For example, prostaglandin analogs and carbonic anhydrase inhibitors used for glaucoma are known to cause stinging upon instillation.
When a Burning Sensation is a Concern
While mild, temporary stinging after applying eyedrops can be normal, a severe, persistent, or worsening burning sensation warrants attention. Discomfort lasting more than a few minutes or increasing in intensity is not typical, and may signal a problem.
Other symptoms accompanying burning can indicate a more serious issue. These include:
Significant eye redness or inflammation
Blurry vision or other vision changes
Pus-like or excessively watery discharge
Sensitivity to light
A feeling that something is in the eye
Swelling of the eyelids or surrounding area
Severe burning can sometimes be part of an allergic reaction to an eyedrop ingredient. Contaminated drops or an underlying eye infection could also lead to severe burning, often accompanied by other symptoms like discharge, pain, or vision changes.
What to Do if Eyedrops Burn
If eyedrops cause a burning sensation, several steps can help manage discomfort. Ensure drops are not expired and stored correctly, as improper storage can lead to irritation. Avoid touching the dropper tip to the eye or any surface to prevent contamination. After instilling the drop, gently close the eye and apply light pressure to the inner corner near the nose for a minute or two to help absorption and prevent drainage.
For sensitive eyes or frequent users, preservative-free options can reduce irritation; these often come in single-use vials to maintain sterility. If irritation persists with a specific eyedrop, discuss alternative brands or formulations with an eye care professional. Seek medical advice if burning is severe, persistent, accompanied by concerning symptoms, or if there is any doubt about the eye’s condition. Do not use other drops or remedies without professional guidance, as this could worsen the problem.