It feels great to upgrade your vision in an instant with contact lenses, but shelling out for them might be a little painful. Those things can be expensive! So, from a financial perspective, you might feel like it makes sense to stretch out how long you wear your lenses. From an eye health perspective…it’s not a good idea.
“It is terrible to wear the same contact lenses for a long, long time,” Alisha Fleming, O.D., an optometrist at Penn Medicine, tells SELF. “Would you go days without brushing your teeth or wear the same underwear for days without washing?”
Well, that confirms your suspicions that contact lenses come with recommended time limits for a reason. But what kind of issues might come up if you blow past those replacement deadlines?
First you should know that the definition of “too long” varies based on the type of contacts you use.
The Food and Drug Administration (FDA) classifies contact lenses as medical devices. As such, the FDA has guidelines on the safest way to use them. One of the biggest is following the manufacturer’s recommended replacement schedule for your individual type and brand.
Contacts come in a few general forms. Daily disposable contacts are typically soft, flexible ones you should only wear once before tossing, the FDA explains. Depending on the brand, you can use extended wear contact lenses safely for up to 30 days. (Some brands are even approved for overnight wear, Vivian Shibayama, O.D., an optometrist and contact lens specialist with UCLA Health, tells SELF, although we'll explain why you may not want to do that in a bit.) Extended wear lenses are usually also soft, although sometimes they’re in a harder form known as rigid gas permeable (RGP) lenses. RGP lenses are less likely to tear, more resistant to build-up, and also often cheaper since you do get to use them for longer, according to the FDA. On the downside, they tend not to be as comfortable as soft lenses, at least to start.
Then there are contacts known as planned replacement lenses, which are soft lenses you swap out on a set schedule, like every two weeks, monthly, or quarterly (instead of throwing them away daily or at some period in the extended wear timeframe), the American Optometric Association (AOA) says.
A few things can happen if you push the recommended lens replacement schedule. None of them are good.
Below, various fates that could befall your eyeballs if you wear your lenses for too long:
1. You might not see as well. Over time, substances like protein deposits, microorganisms, and allergens develop on the surface of your contacts, the AOA says. While tactics like cleaning your lenses every day and following good contact lens case hygiene help prevent this, it will still happen eventually if you, say, use your daily disposables for a full week. Over time, this could cause issues like blurry vision, Dr. Shibayama says. You might also start to experience a burning sensation when you insert your contacts due to all that build-up.
2. Your eyes can become dry and irritated. Even if your eyes are usually perfectly slick, wearing contact lenses can make them more prone to dryness. That’s why wearing contacts is a risk factor for the health condition dry eye. Dry eye essentially means the tear film that keeps your eyes wet isn’t plentiful enough, isn’t the right composition, or ghosts your eyeballs by evaporating too quickly, the National Eye Institute explains. This can cause symptoms like burning, stinging, and sensitivity to light, among others. (It’s actually a surprisingly long list.) If you already have dry eye, wearing contacts can make it worse—especially if you ignore that replacement schedule.
Wearing lenses past their prime can make it harder for your contacts to stay as wet as they need to in order for you to wear them comfortably, Dr. Shibayama says. Doctors see this pretty often. “A lot of patients have complaints of discomfort and their eyes feeling dry at the end of the day and they come in looking for a magical solution,” Dr. Fleming says. “Often times, it’s as simple as practicing proper hygiene and lens replacement to optimize comfort.”
3. You can get an infection. Your contacts aren’t made of a magical substance that’s designed to last for all eternity. Nope, they’re basically just plastic.
“Lens materials start to break down after their approved wear period,” Ann Morrison, O.D., clinical instructor in The Ohio State University College of Optometry, tells SELF. This can allow other materials—including infection-causing pathogens—to more easily infiltrate the lenses, she explains. Combined with the fact that microorganisms and allergens build up on your lenses over time, this increases your risk of an eye infection like infectious keratitis. Infectious keratitis is an inflammation of your cornea (that bit of your eye that your contact lens covers) that happens due to bacteria, fungi, or parasites, according to the Mayo Clinic. Contaminated contacts are a major potential cause.
This is also something doctors deal with pretty often. Wearing lenses longer than prescribed is one of the most common reasons Dr. Shibayama sees patients with eye infections, she says. Things get even worse if wearing your contacts for too long involves sleeping in them—that blocks oxygen flow to your eyeballs at night, which can lead to some serious irritation and possible infection. This can be an issue even if your lenses are technically FDA-approved for overnight wear, Dr. Shibayama says, so it's probably best to pop them out while you sleep anyway.
Is it possible to stretch the replacement schedule of your lenses and be just fine? Sure. But you’re taking a risk, and your eyes are kind of important.
If you’re doing this for cost-saving reasons, talk to your doctor about switching to a more economical brand or looking into whether or not you can open up a health insurance savings plan, like a flexible spending account, so that you can use untaxed money from your paycheck to buy your contacts. And if you’re still waffling on how much it matters to change your contacts on time, remember this gem from Dr. Morrison: “I always tell my patients that the cost of treating complications from contact lens overwear can cost far more than the cost of replacing the lenses appropriately.”