What Happens If You Wear Contact Lenses Past Their Replacement Date?

Keeping your contact lenses past their replacement date raises the risk of discomfort and complications, such as an infection of the cornea. Comfort is not enough: follow the prescribed schedule. If you went past the date, take your lenses out and open a new pair; if your eye is red or painful, call your optometrist.

What is a contact lens replacement date?

It is the point when a lens has to be thrown away and replaced with a new one. According to the Centers for Disease Control and Prevention (CDC), most soft contact lens wearers must replace their lenses on a schedule prescribed by their eye care provider: one day for daily lenses, 7 to 30 days for planned replacement lenses.

The American Academy of Ophthalmology (AAO) describes lenses that are replaced every day, every week, every two weeks or every month. Our article on daily vs monthly contact lenses compares these schedules.

What happens if you wear contact lenses too long?

The risk of discomfort and complications goes up. The CDC says that wearing contact lenses longer than the recommended replacement schedule can lead to eye discomfort or other complications. It adds that germs such as bacteria, fungi or amebae are more likely to invade the eye when lenses are worn for too long or not cared for correctly.

Those germs can cause microbial keratitis, an infection of the cornea that, in the most severe cases, can lead to blindness or a corneal transplant, according to the CDC. The CDC also notes that most complications can be easily treated when you get seen.

Why replace a lens that still feels fine?

Because comfort does not tell you whether the lens is still good. The Canadian Association of Optometrists (CAO) says to wear your contacts only for the length of time recommended, even if they feel comfortable, and to remove, clean and disinfect them at the intervals prescribed. The AAO says to keep the schedule your eye doctor gives you for wearing and replacing your lenses.

Our article on how many hours a day you can wear contacts covers the same rule for daily wearing time.

Is it common to keep lenses too long?

Yes. In a University of Waterloo study published in 2011, 501 silicone hydrogel lens wearers from seven optometry offices were surveyed: two in three wore their lenses longer than the manufacturer recommended. Lens-related problems were more common among those who did not follow their optometrist's schedule.

In the United States, a CDC survey of about 1,000 wearers published in 2015 found that close to half said they had replaced their lenses later than recommended at some point.

Can you wear daily contact lenses for two days?

No. According to the CDC, a daily disposable lens is used once: you throw it away each night and put in a new pair the next morning. Wearing it for more than one day may cause discomfort or other complications.

A daily lens is not designed to be cleaned and stored in a case for the next day. If you wear lenses once in a while, keep a supply of new pairs rather than reusing the same one.

I went past the date: what should I do now?

Take your lenses out and switch to a new pair. The CDC says to replace your lenses as often as your eye care provider tells you. If you are out of new lenses, wear your glasses in the meantime, as the CDC advises always carrying a pair of glasses with you.

If your vision is blurred or your eye hurts, Health Canada says to take your lenses out right away and, if it does not go away within a few hours or gets worse, contact your eye care professional or go to the emergency department.

Which signs mean you should call right away?

A red, irritated eye, pain that gets worse even after you take the lenses out, light sensitivity, sudden blurry vision, unusually watery eyes or discharge. These are the signs the CDC lists; it says to remove your lenses and call your eye doctor immediately.

The FDA adds not to put those lenses back in and not to throw them away: store them in their case and bring them, since your eye care professional may use them to find the cause. Our urgent eye care page explains what to do first.

What about the case and the solution?

Replace the case at least every three months, according to the CDC and the AAO, and right away if it cracks or gets damaged. The CDC says to clean it with solution, let it dry upside down with the caps off, and never mix fresh solution with old solution.

The FDA says to throw out all the solution after each use and never to reuse or top it off. Our article on contact lens care goes through each step.

What if my prescription has expired?

Have your eyes checked before you order. According to the Ordre des optométristes du Québec (OOQ), how long a prescription is valid is up to the optometrist's judgment and, for ophthalmic lenses, should normally not be less than one year. The FDA advises against ordering lenses with an expired prescription or stocking up right before it expires.

Our article on contact lens prescriptions explains what the numbers mean and how long a prescription is valid.

Where can you renew your contact lenses in Montréal?

At PrimeVision, 9520 Boulevard de l'Acadie, Suite 222, in Montréal (Ahuntsic), optometrists and a licensed optician work under one roof. The clinic fits silicone hydrogel soft contact lenses, and your lenses' replacement schedule is set at the fitting. Most trial lenses are available the same day when in stock, otherwise in 2 to 5 business days, and the follow-up after a first fitting usually takes place a few days to a week later. RAMQ covers eye exams for children under 18 and adults 65+.

Our page on contact lenses in Montréal covers fittings and trial lenses. For an up-to-date prescription, book an eye exam.

Sources

• About Contact Lens Types, Centers for Disease Control and Prevention, 2025.
• What Causes Contact Lens-related Eye Infections, Centers for Disease Control and Prevention, 2025.
• Preventing Eye Infections When Wearing Contacts, Centers for Disease Control and Prevention, 2025.
• Contact Lens Wearer Demographics and Risk Behaviors for Contact Lens-Related Eye Infections, United States, 2014, MMWR, CDC, 2015.
• Dumbleton KA, Woods CA, Jones LW, Fonn D. The relationship between compliance with lens replacement and contact lens-related problems in silicone hydrogel wearers. Contact Lens and Anterior Eye, 2011.
• Wear and Care for Contact Lenses, Canadian Association of Optometrists.
• How to Take Care of Contact Lenses, American Academy of Ophthalmology.
• Contact Lenses for Vision Correction, American Academy of Ophthalmology.
• Contact Lens Risks, U.S. Food and Drug Administration.
• Everyday Eye Care, U.S. Food and Drug Administration.
• Buying Contact Lenses, U.S. Food and Drug Administration.
• Contact lenses, Health Canada.
• Questions fréquentes : droits du patient et obligations professionnelles, Ordre des optométristes du Québec (in French).