Preservatives in saline solution?

Dear Alice,

As an avid contact wearer, I use saline solution to rinse my contacts daily before each use. Recently, a friend told me that many commercial saline solutions contain preservatives, which could affect the overall health of my eye. Is this something I should be concerned about? The saline I use has always felt comfortable so I never thought it could pose a problem.

— teary eyed and tentative

Dear teary eyed and tentative,

With so many different eye drops and contact lens solutions out there, the "solution" to the question of which one is the healthiest for your eyes can be a bit… cloudy. But the short answer is that preservatives in saline are low risk to the health of your eyes, as long as they don't cause irritation and your health care provider has approved the use of the solution for your lenses. If you're experiencing irritation in your eye, it’s best to seek treatment as soon as possible to minimize the chance of any long-term damage to the eye. To prevent eye discomfort due to your contacts, it may be a good idea to ask your health care provider if your lenses and your solution are safe to use together.

Preservatives are used in eye drops and contact lens solutions as a way to slow the growth of bacteria in the opened bottle. Different individuals have different levels of sensitivity to these preservatives. Recently, there have also been more solutions on the market that are advertised as “multi-purpose” in that they not only condition and lubricate the lenses, but they can also disinfect. Being able to do all of this requires a variety of chemicals. As a result, more individuals reported sensitivities because of the exposure to more chemicals. People who are sensitive to different ingredients, such as thimerosal (a preservative), in contact solution may experience itchy, watery, or red eyes, and in some cases eyelid swelling. If you do experience these symptoms or pain for more than a day or two, it’s best to talk with your health care provider because if left untreated, eye infections can lead to permanent damage or loss of vision.

Usually, switching to a "sensitive eyes" or a "thimerosal-free" saline solution may provide some relief as these products likely don’t contain the chemicals that irritate your eyes. If you do switch to a preservative-free solution, it’s a good idea that with these types (and really all eye solutions) to carefully abide by the expiration date and dispose of these products by the indicated date to avoid eye infections. You might also consider buying a smaller bottle of solution since the preservative-free options will expire more quickly, thereby minimizing the amount of solution wasted.

Additionally, although it may work great for gargling and for neti pots, it's not safe to use homemade saline solutions for contact lenses, nor is it safe to use distilled water, tap water, or saliva. All of these other substances are prone to growing bacteria (especially saliva) and will likely cause eye irritation. Your best bet is to stick with an eye care provider-approved solution. After all, the eye is one of the most intricately designed and sensitive sensory instruments on the human body and deserves the greatest of care.

Here's to preserving the health of your eyes!

Last updated Aug 09, 2019
Originally published Nov 25, 2011