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Preservatives, a Friend or Foe? - Why Your Eye Sting After Using Eye Drops

Living with dry eyes can be a frustrating experience that lowers the quality of daily life [1]. Your patients may have experiences of using lubricating eye drops, the recommended first-line treatment for dry eye relief [2], but finding their eyes irritated even more. Why do the eyes hurt after using eye drops? Here may be the reason why.

As lubricating eye drops are opened and used, unfortunately they come in contact with the air. This leads to potential contamination of the eye drops after a certain period of time. To prevent this, modern lubricating eye drops contain preservatives. But at the cost of avoiding microbial contamination, preservatives have side effects that may further upset the symptoms of dry eyes. [3]

Preservatives irritate your eyes even more

A woman feeling irritation in her eyes after using preservative-eye drops.

Benzalkonium chloride (BAK) is one of the most commonly used preservatives in lubricating eye drops, and long-term use of BAK induces toxic, negative effects on the eyes. [4] This detergent can damage the cells of the eye surface [5], destroy the natural tear film [6], and be the cause of intolerance reactions such as discomfort, increased tearing, increased dryness, and sometimes, greater severity of existing eye diseases [3,7]

Preservative-free eye drops are one of many different solutions to avoid the risk of potential irritations caused by preservatives. But preservative-free drops are often available in single-use containers or multi-dose bottles that have a relatively short shelf-life and are inconvenient to use. [8] Are you looking for preservative-free eye drops with a long in-use sterility? Then, preservative-free HYLO® family of lubricating eye drops may be the ideal choice.

Why you should choose HYLO® family

Preservative-free HYLO® family of lubricating eye drops, combined with high-quality sodium hyaluronate, provides non-irritating, immediate, and long-lasting relief of dry eyes. The safe, German-engineered airless, multi-dose bottle system ensure no entry of air into the bottle, providing full sterility of the contents for six months after the first drop without the use of preservatives.

HYLO® family of lubricating eye drops are available for healthcare professionals and patients across Canada. Try now and feel the difference!

CandorVision™ - Your Eyes Are Everything


  1. Uchino M, Schaumberg DA. Dry Eye Disease: Impact on Quality of Life and Vision. Curr Ophthalmol Rep. 2013 Jun;1(2):51-57. doi: 10.1007/s40135-013-0009-1. PMID: 23710423; PMCID: PMC3660735.

  2. Craig JP, Nelson JD, Azar DT, Belmonte C, Bron AJ, Chauhan SK, de Paiva CS, Gomes JAP, Hammitt KM, Jones L, Nichols JJ, Nichols KK, Novack GD, Stapleton FJ, Willcox MDP, Wolffsohn JS, Sullivan DA. TFOS DEWS II Report Executive Summary. Ocul Surf. 2017 Oct;15(4):802-812. doi: 10.1016/j.jtos.2017.08.003. Epub 2017 Aug 8. PMID: 28797892.

  3. Pisella PJ, Pouliquen P, Baudouin C. Prevalence of ocular symptoms and signs with preserved and preservative free glaucoma medication. Br J Ophthalmol. 2002 Apr;86(4):418-23. doi: 10.1136/bjo.86.4.418. PMID: 11914211; PMCID: PMC1771067.

  4. Baudouin, C., de Lunardo, C., 1998. Short-term comparative study of topical 2% carteolol with and without benzalkonium chloride in healthy volunteers. Br. J. Ophthalmol. 82, 39e42

  5. Epstein, Seth P et al. “Comparative toxicity of preservatives on immortalized corneal and conjunctival epithelial cells.” Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics vol. 25,2 (2009): 113-9. doi:10.1089/jop.2008.0098

  6. Ishibashi T, Yokoi N, Kinoshita S. Comparison of the short-term effects on the human corneal surface of topical timolol maleate with and without benzalkonium chloride. J Glaucoma. 2003 Dec;12(6):486-90. doi: 10.1097/00061198-200312000-00008. PMID: 14646684.

  7. Jaenen N, Baudouin C, Pouliquen P, Manni G, Figueiredo A, Zeyen T. Ocular symptoms and signs with preserved and preservative-free glaucoma medications. Eur J Ophthalmol. 2007 May-Jun;17(3):341-9. doi: 10.1177/112067210701700311. PMID: 17534814.

  8. Furrer P, Mayer JM, Gurny R. Ocular tolerance of preservatives and alternatives. Eur J Pharm Biopharm. 2002 May;53(3):263-80. doi: 10.1016/s0939-6411(01)00246-6. PMID: 11976014.



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