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You might use eye drops for many different reasons, including ocular allergies, eye redness, and dry eye. Any eye drop bottle that you open and use more than once will contain preservatives. Preservatives can help prevent the growth of bacteria in the bottle that contains the drops.
The most common preservative used in eye drops is called benzalkonium chloride, or BAK. Using BAK too frequently can irritate your eyes and may make dry eyes worse. Eye drops for dry eye that are free of preservatives do not contain BAK. If you have dry eye and you are an ongoing eye drop user, you may prefer a preservative-free option.
This article will address dry eyes, preservative-free eye drops, and when it's best to use preservative-free eye drops.
Dry Eyes and Eye Drops
Dry eyes occur are when your eyes do not make enough tears or the tears that they make are of poor quality. Dry eyes can have many causes, including:
- Being female
- Using contact lenses
- Having certain medical conditions like diabetes (chronic condition affecting how your body uses glucose, or blood sugar) and rheumatoid arthritis (an autoimmune disease affecting the joints)
- Hormonal changes
- Living or working in a dry environment
- Older age
- Using certain medications that dry out your eyes
Different types of eye drops are used for dry eye to help relieve symptoms of dryness. Artificial tears, also called lubricating eye drops, may be used several times a day when you have dry eye. These types of drops provide the eyes with some of the same natural elements that your tears have. Artificial tears are sold over the counter. Many artificial tears contain preservatives.
Popular prescription eye drops for dry eye do not contain preservatives, such as Cequa or Restasis (cyclosporine ophthalmic solution) and Xiidra (lifitegrast). Prescription eye drops treat dry eye in a different way and are not considered to be artificial tears.
What Are Preservative-Free Eye Drops?
There are artificial tears for dry eye with and without preservatives. Benzalkonium chloride is the most common preservative in eye drops. However, in some people, BAK can make dry eye worse. Other possible effects from BAK include:
- Discomfort when instilling the drop
- Feeling as if you have something in your eye
- Itchy eyelids
Some lubricating eye drops contain preservatives, while others do not. Eye drops with preservatives typically are sold in small bottles. Each time you want to use the product, you open the bottle, insert the eye drop, and close the bottle until you use it again. The preservative helps to prevent the growth of bacteria.
Do They Cost More?
As the term suggests, preservative-free eye drops do not contain preservatives to keep bacteria away. To help avoid bacterial growth, eye drop manufacturers usually package preservative-free eye drops in single-use vials instead of using the same bottle multiple times.
Because of this, preservative-free eye drops cost more than those with preservatives. Some preservative-free drops are now made in multidose bottles so you can use them more than once, but these are not as common as the single-use vials.
Are There Low-Preservative Options?
Some lubricating eye drops are made with what are called soft preservatives, such as sodium chlorite, sodium perborate, and polyquaternium-1. Although these are less irritating to the eye, many eye specialists still support using preservative-free eye drops, especially if you require eye drops several times a day.
When to Use Preservative-Free Eye Drops
You may want to consider using preservative-free eye drops for dry eye if any of the following apply to you:
- You have glaucoma, a group of eye conditions that damage the optic nerve, which is necessary for vision. (This is because you may be using other eye drops to treat your glaucoma, and those may have BAK in them. Adding more drops with preservatives like BAK can further irritate your eyes.)
- You use artificial tears more than four times a day.
- You know that you have moderate to severe dry eye.
- You have serious eye allergies or you know you are allergic to BAK or another preservative used in eye drops.
- You wear contact lenses.
- You spend a lot of time using electronic devices, which may dry out your eyes more.
Many eye drops contain preservatives. The most common preservative, BAK, can irritate the eyes for some. If you use lubricating eye drops frequently for dry eye, you may want to switch to preservative-free eye drops. Also consider switching to preservative-free drops if you use electronic devices frequently or have glaucoma.
A Word From Verywell
The number of lubricating eye drops available over the counter can be overwhelming. While they are a slightly more expensive option, preservative-free eye drops can help you avoid the preservative BAK, which may irritate your eyes further. Your doctor may recommend them if you have an advanced case of dry eye.
See if you can find coupons for preservative-free eye drops, or ask your eye doctor if they know of discounts available for preservative-free drops. Most flexible savings accounts (FSA) cover the cost of eye drops, as well.
Frequently Asked Questions
- How long can you use preservative-free eye drops?
Follow any guidance on the packaging for how long you can use preservative-free eye drops. Many of them are sold in vials meant to be used just once or within 24 hours after they are open. If the drops are unopened, read the packaging to find out when the drops will expire.
- Can I reuse preservative-free eye drops?
Read the product packaging to find out. Preservative-free eye drops come in packaging for onetime use or use within 24 hours. Prolonging their use can increase the chance of bacterial contamination.
- Can I use preservative-free eye drops every day?
Yes, it is safe to use preservative-free eye drops every day.
- Are preservative-free eye drops harmful?
They are not harmful. Follow any recommendations from your eye professional on using preservative-free eye drops. If you are not yet treated for dry eye, see an eye doctor if you are using the drops more than four times daily.