Decongestant eye drops refer to liquid medications used to alleviate the symptoms of eye allergy, which include tearing, burning sensation, itchiness, red eyes, swollen eyelid, and a feeling that something is in the eye. In very rare cases, eye allergies can cause blurry vision and discolored skin under the eye. These symptoms are known as allergic conjunctivitis and are more common with seasonal allergies.

About 40% of Americans are affected by eye allergies. Some people are prone to allergic reactions when their immune system mistakes a harmless allergen (substance causing the allergy) for a harmful substance. This sends the immune system into overdrive to fight the intruder by producing histamine, a molecule, and the result is an allergic reaction. The allergens or irritants can be found both indoors and outdoors. Indoor allergens cause a year-round allergic response and include dander from pets, mildew, mold, and dust mites. People notice the allergic reaction when they perform tasks or activities that set the allergens in motion, such as cleaning dusty rooms, brushing a pet, etc. Outdoor allergens are seasonal and associated with changes in nature, such as pollen from grass, weeds, and trees. People may notice that the allergic reactions are more when they are outdoors during springtime when there is a proliferation of pollen. Besides allergens, contact lenses and certain medications may trigger an allergic reaction.

Decongestant eye drops provide temporary relief from redness due to the vasoconstrictors contained in them. These vasoconstrictors shrink the eye’s blood vessels and brighten the sclera (eye’s white part). Some decongestant eye drops contain antihistamines, which helps to relieve itchiness. Decongestant eye drops can be found over the counter or be prescribed by the health care provider. Several factors, such as symptom severity and cause of the allergy, will inform one's choice of these eye drops. 

Examples of decongestant eye drops without a prescription include naphazoline, oxymetazoline, phenylephrine, and tetrahydrozoline. 

Administration & Dosage

Some of the decongestant eye drops are designed to treat acute symptoms in the short-term. Others are meant for long-term use to decrease sensitivity to allergens or as a preventive measure. 

The dosage depends on the instructions on the label, which should strictly be followed or as directed by the physician. Compliance minimizes the risk of side effects such as irritation. A visual inspection of the product is necessary so that if there is evidence of color change, it should be discarded. Usually, one administers two to three drops a day. Some medications may be taken up to four times per day. Should the individual experience increased irritation or redness, it’s best to stop the medication and consult a doctor right away. 

To administer the eye drops, the hands should first be thoroughly cleaned. The dropper should not be touched to avoid contaminating the medication. The dropper should also not come into contact with another surface or touch the face. With the head tilted, the person looks up and creates a pouch by pulling the lower eyelid down. The dropper is held directly over the eye, followed by placing one drop into the pouch. Closing the eyes for a minute or two after looking down and gentle application of pressure using the finger will help the person retain the medicine in the eye. Blinking or rubbing the eye should be avoided. Meanwhile, the dropper should not be rinsed, and instead, the cap is replaced tightly after each use. 

In case one is using contact lenses, they should be removed before the application of the drops. A waiting period of ten minutes is recommended after using the drops before placing back the lenses. The same principle applies to the concurrent use of the medication. If one is on other drugs, s/he can wait for at least five minutes before applying other eye medications. Eye Drops should be used first before eye ointments to permit the drops to enter the eye. 

Potential Side Effects & Interactions

There is the risk of eye swelling and redness, which continues even when the medications have been stopped. People with glaucoma are forbidden from using decongestant eye drops. This is because decongestants can dilate the pupil, which is very dangerous for people with an anatomically narrow anterior chamber angle, causing an acute glaucoma attack. 

Symptoms of Overdose

Decongestant eye drops are used in the short-term for only about three days. Overusing these drops predisposes the patient to dependency such that even more severe redness results once treatment is discontinued. It is called rebound redness or rebound hyperemia. This will cause the person to reach out for the eye drops and continue with a vicious cycle.


The medication is stored as indicated on the packaging and should be kept away from children and pets.