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Understanding Red Eyes: Why Whitening Eye Drops Aren't the Solution for Dry Eye

Person with red eyes and how vasoconstrictors may not help dry eye

If you have red eyes you might want to think again before reaching for whitening eye drops – these contain vasoconstrictors which won’t help your dry eye.


Red, sore looking eyes are a common symptom of dry eye, and can be both annoying and embarrassing. It can be tempting to go for a quick fix and reach for a whitening eye drop, which contain vasoconstrictors, but these will not help address your dry eye and longer term may make your dry eye and eye redness worse. Learn more here:


What causes red eyes

There are many potential causes of red eyes and your eye care professional will want to establish the reason for the redness before recommending a treatment. The redness could be caused by an infection, an allergy, an irritant such as smoke or air pollution, simple fatigue – or for many inflammation due to dry eye is the cause. Dry eye is caused by an insufficient quantity and quality of tears, so simply getting rid of the redness will only provide temporary redness relief and will not address the root cause of the problem.


What is happening to make my eyes red

The conjunctiva is a thin clear membrane that covers the the white area of your eye and runs up the inside surface of your eyelids . It contains blood vessels which help supply your eye with food and oxygen. When these tiny vessels dilate, in response to an inflammatory trigger, they do this in order to get more blood to the eye – this brings antibodies, oxygen and nutrients.  Because dry eye is a progressive inflammatory condition red eyes can be a symptom.


What exactly is a vasoconstrictor

A vasoconstrictor or ocular decongestant is a chemical which causes the blood vessels to become narrower or constrict. They are found in eye drops which are indicated to relieve red eyes, the most common ones are tetrahydrozoline, naphazoline, and brimonidine. Although these eye drops are generally safe to use occasionally, they may not be the most appropriate for someone with dry eye.


How do vasoconstrictors work

The vasoconstrictor will bind to sites in the walls of the ocular blood vessels, this results in the muscles in the blood vessel walls contracting. This has the effect of reducing the amount of blood in the conjunctiva so your eyes appear whiter.


Why are they not ideal for dry eye sufferers

When the effects of the whitening eye drops wear-off, after around 6-8 hours, your eyes can appear even redder than before, this is known as the ‘rebound effect’. This effect is due to your eyes over compensating for the lack of nutrients and oxygen while the blood vessels were contracted. Some eye care professionals have concerns that if you start to use vasoconstrictors routinely you will be causing damage to the surface of the eye.

But perhaps just as importantly you are not tackling your dry eye disease, instead the condition is being left to potentially get worse. There have also been scientific studies which show the tear quality maybe negatively impacted by vasoconstrictors and long-term use can actually cause severe dry eye. Add to that the risk of the rebound effect leaving you with permanently red eyes and you’ll see why these drops are bad news.


Beware of preservatives: Dry Eye Zone had a look at some of the eye whitening eye drops on the market and were concerned to see that some older generation preservatives were still being used, such as benzalkonium chloride (BAK). BAK is toxic to ocular tissue and regular use can cause irritation, ocular surface damage and potentially make dry eye worse.


Whiter looking eyes for the dry eye sufferer

If you have dry eye your natural protective tears are reduced in quality and quantity. This physiological change starts a cycle of inflammation, part of which will be the dilation of your conjunctival blood vessels. To address these symptoms you need to take steps to improve your natural tears – when you do you will notice this redness subside and your eyes appear whiter.


Caring for your dry eyes starts with a dry eye drop

Use a preservative free dry eye drop throughout the day, you do not have to wait for symptoms to become established. Just by ‘plumping’ up your natural tears you will help to stop the inflammatory reaction, including returning the natural balance to the conjunctival blood vessels. However, if you have persistent red eyes you must visit your eye care professional so they can check what is causing this problem.


You can find out how to improve the quality of your natural tears in order to combat the effects of dry eye disease by visiting Dry Eye Zone – where you will find plenty of useful advice, more about dry eye disease and a curated range of products you will only find available from leading independent opticians. And don’t forget to subscribe to Dry Eye Zone regular free information updates.



If you are experiencing dry eye symptoms then you should ask the advice of your eye care professional. Do not leave things untreated as symptoms may progress. Why not book your next eye examination with an independent optician today.




Eye-Whitening Drops: Are They Safe? By Nicole Hollimon. Medically Reviewed by Whitney Seltman, OD.8 November 2022.


Golden MI, Meyer JJ, Patel BC. Dry Eye Syndrome. [Updated 2023 Apr 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from:


Hosten LO, Snyder C. Over-the-Counter Ocular Decongestants in the United States - Mechanisms of Action and Clinical Utility for Management of Ocular Redness. Clin Optom (Auckl). 2020 Jul 23;12:95-105. doi: 10.2147/OPTO.S259398. PMID: 32801982; PMCID: PMC7399465.


Sarfaroj Khan, BHMS, PGD Health Operations. HOW DO OPHTHALMIC DECONGESTANTS WORK? Accessed 12 February 2024.


Göbbels M, Achten C, Spitznas M. Einfluss vasokonstriktiver Augentropfen auf Tränenvolumen und Tränensekretion [Effect of vasoconstrictor eyedrops on tear volume and tear secretion]. Fortschr Ophthalmol. 1991;88(2):173-5. German. PMID: 1855740.


Dr. Edward Jaccoma. Can I use eye “whiteners” (like Visine or Lumify) when my eyes get red? Jul 2


Semp DA, Beeson D, Sheppard AL, Dutta D, Wolffsohn JS. Artificial Tears: A Systematic Review. Clin Optom (Auckl). 2023 Jan 10;15:9-27. doi: 10.2147/OPTO.S350185. PMID: 36647552; PMCID: PMC9840372.


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