It is possible to taste eye drops, a common and real physiological phenomenon. This occurs because the eye is anatomically connected to the back of the throat, allowing the liquid to travel from the eye surface to taste receptors.
The Nasal Connection
The anatomical pathway that allows eye drops to reach the back of the throat involves the nasolacrimal duct system, often referred to as the tear duct. Small openings, called puncta, are located in the inner corner of both the upper and lower eyelids. These puncta lead into tiny tubes, the canaliculi, which then empty into a larger reservoir known as the lacrimal sac. From the lacrimal sac, a canal called the nasolacrimal duct extends downwards, opening into the nasal cavity. Once in the nasal cavity, the liquid can then drain into the back of the throat, where it can be tasted.
Why Eye Drops Have a Taste
The distinct taste experienced from eye drops comes from various components within their formulation. Eye drops contain active medicinal ingredients, preservatives, and other agents like buffering and tonicity agents. Each of these substances can contribute a unique flavor, such as bitter, metallic, or salty.
For instance, certain antibiotic eye drops, including polymyxin and neomycin, are frequently associated with a bitter taste. Preservatives, such as benzalkonium chloride, are added to prevent bacterial contamination and can also impart a taste. Some eye drops may also contain taurine, which can contribute to the taste sensation. Additionally, specific medications like dorzolamide are well-known for causing a metallic taste.
Is Tasting Eye Drops a Concern?
In most instances, tasting eye drops is a normal occurrence and generally not harmful, as the amount of medication that drains into the throat is typically very small. However, tasting eye drops can indicate that some of the medication is being absorbed systemically, meaning it enters the bloodstream. While this systemic absorption is usually insignificant for most eye drops, it can sometimes increase the potential for side effects, particularly with certain medications. Accidental ingestion of larger quantities, especially by children or pets, can be a concern for over-the-counter red-eye drops. Swallowing these in substantial amounts can lead to serious effects such as drowsiness, a slow heart rate, or low blood pressure.
Strategies to Avoid the Taste
Several techniques can help minimize the taste of eye drops. One widely recommended method is punctual occlusion, which involves applying gentle pressure to the inner corner of the eye after administering the drops. This pressure effectively closes the puncta, blocking the drainage pathway into the nasolacrimal duct. Holding this pressure for 30 seconds to one minute helps keep the medication on the eye’s surface, allowing for better absorption and reducing the amount that travels to the throat.
Another tip is to close the eyes gently for a few moments, avoiding excessive blinking, as blinking can act like a pump and push the liquid into the drainage system. Tilting the head slightly backward can also help prevent drainage. Newer products, like those with specialized applicators, are designed to deliver smaller, more precise drops, which can further reduce the amount of excess liquid available to drain.