There’s a lot to love about contact lenses. They’re convenient and easy to use. And let’s face it: While glasses are great, sometimes you just want to look like, well, you. 

All good things aside, the decision to wear contacts isn’t something to be taken lightly. Contact lenses are classified as medical devices by the U.S. Food and Drug Administration (FDA), and that calls for some serious responsibility. 

Contacts need to be cleaned and replaced on a regular basis. Wearing them incorrectly — or buying them online without a prescription — can cause serious, painful eye infections, some of which can result in vision loss. In other words: You need to take very good care of them. 

Here’s everything you need to know. 

What are contact lenses? 

Contact lenses are clear, thin disks that are designed to be worn in the eyes. Like eyeglasses, contact lenses correct vision problems like nearsightedness and farsightedness. 

Because contacts are medical devices, however, you’ll need a prescription from an eye doctor — like an optometrist or ophthalmologist — to wear them. (And yes, that also includes decorative lenses, also known as costume lenses, or Halloween lenses.) 

Did you know that contact lens prescriptions need to be renewed every year? Now’s the time to book your eye exam!

What are the types of contact lenses? 

There are two main types of contact lenses: hard and soft, with the latter being the most popular option. About 90% of people who wear contacts choose a soft version, according to the Centers for Disease Control and Prevention (CDC). 

Soft contact lenses 

Most people who wear contacts opt for soft lenses, in part because they tend to be the most comfortable option.  

There are multiple types of soft contacts, including: 

Daily-wear lenses: As the name implies, these contacts are made to be worn for only one day. Simply pop them in in the morning and throw them away at night (no contact lens case necessary). 

These lenses are particularly popular not just among people who wear contacts but with eye doctors too. The reason: Most people don’t use contacts properly — they either wear them for too long, don’t clean them correctly, or don’t clean them often enough. Using a new, clean lens every day can help prevent eye irritation and infections. 

“One-day lenses are the easiest way to keep the patient healthy and safe, because it’s a brand-new sterile lens every day,” says Patrick Schrepel, O.D., an optometrist at Doctor’s Exchange of Georgia, P.C., located inside America’s Best Contacts & Eyeglasses. 

Planned replacement contact lenses: Soft contacts are also available as weeklies or monthlies, which are disposed of after two weeks or one month. Unlike daily lenses, which are thrown out at the end of the day, weeklies and monthlies need to be cleaned and disinfected at night, since you’ll be putting them back into your eye the next morning. One benefit: Reusable lenses are usually less expensive than daily-wear versions, says Dr. Schrepel. 

Extended-wear and continuous-wear contact lenses: You’ll be hard-pressed to find an eye doctor who recommends sleeping in your contacts. That’s because there’s a higher risk for an eye infection. But if you do tend to fall asleep with your lenses in, you may want to talk to your doctor about extended-wear contacts, some of which can be worn continuously, including overnight, for up to 30 days. 

The problem with leaving your contacts in overnight — or for a week at a time — is that you’re keeping your eye from getting the oxygen and hydration it needs to fight a bacterial or microbial invasion. Bacteria can become trapped between your eye and the contact lens, where they can reproduce and possibly cause an infection, says Dr. Schrepel. 

“When the lens is in there for eight hours, that’s usually not enough time for a bacteria colony to establish,” he says. “You need about 24 hours for bacteria colonies to really start replicating. That’s when the risk goes up.” 

Monovision contact lenses: Sooner or later, almost everyone over the age of 40 will develop presbyopia, an eye condition that makes it harder to see objects up close. Reading glasses aren’t your only option, however — monovision contact lenses can also correct presbyopia. (For more on alternatives to reading glasses, click here.) 

With monovision contacts, one lens is corrected for distance and the other is corrected for near vision. (For example, the left eye can see things far away, and the right one can see things up close.) Together, both eyes allow you to see clearly at any distance. 

Sound intimidating? Don’t worry — most people subconsciously prefer to use one eye to see far off in the distance and the other to look at things up close. Plus, people usually adjust pretty well to these types of contacts after a week or two. 

Multifocal contact lenses: Multifocal contact lenses correct both near and far vision in both lenses, allowing you to see up close and off in the distance with both eyes. 

Unlike multifocal eyeglasses, which correct for near vision at the bottom of the lens (hence having to look down to read), multifocal contacts have the prescription in different areas throughout the lenses, so you can read in multiple positions, not just by looking down. Your brain will adapt to the different focuses in the lenses, though it may take one to two weeks. Your optometrist can give you some tips for easing into the adjustment process. 

Toric contact lenses: These contacts correct for astigmatism, which is a misshapen cornea. Toric lenses are designed to rotate the angle of focus on the front of the eye’s lens to correct for the myopia (nearsightedness) or farsightedness that comes with astigmatism. They can be more expensive than other options. 

Colored contact lenses: Also called tinted lenses, colored contact lenses change the appearance of your eye color while also correcting your vision. (Popular colors include blue, green, and gray.) They’re available as daily-wear and extended-wear lenses. 

Decorative contact lenses: Decorative contacts are often worn as part of a Halloween costume, which is why they’re also called costume lenses. They can change the appearance of your eyes’ color or shape — giving you, for example, green catlike eyes or red vampire-like eyes. Decorative contacts are available by prescription. (Purchasing nonprescription contact lenses online is illegal in the United States.) 

One of the many reasons that decorative contacts are so dangerous? They’re sometimes marketed as “one size fits all” — even though there’s no such thing for contact lenses. Contact lenses that don’t properly fit your eyes won’t be comfortable — and they can scratch your cornea (the surface of the eye), or cause infections or even blindness. 

Hard contact lenses 

Rigid (i.e., hard) contact lenses were first produced in the United States between 1938 and 1940, and they were made from plastic. Hard contacts have improved over the years, however. 

Today, the most common type of hard contact lens is called a rigid gas-permeable (RGP) lens, which is made of plastic and other materials. The current RGPs are also particularly breathable, allowing oxygen to pass through the lens and reach the eye. 

Hard contacts are — you guessed it — less flexible than soft contacts, but their firmness has some benefits: They can provide sharper vision for some people, especially those with astigmatism, a condition in which the eye’s cornea is curved, causing blurry vision. 

RGPs also tend to be more durable, easier to handle, and less likely to tear than soft contacts. But they’re also more complicated to fit, says Dr. Schrepel. “Everything has to be custom-made to that person,” he says. 

Curious about contact lenses? Browse our extensive selection and learn how you can save on an annual supply with our Eyecare Club.
 

Who wears contact lenses?  

An estimated 45 million people in the United States wear contacts, according to the CDC. About 75% of contact wearers are age 25 or older, about 17% are between the ages of 18 and 24, and 8% are under 18. 

About 2 in 3 people who wear contact lenses are female, according to the CDC. 

How does your eye doctor determine the best contact lenses for you? 

Given all the various types of lenses available, your eye doctor bases their recommendation on a few different factors, beginning with how your vision needs to be corrected. Do you have presbyopia? They may suggest monovision or multifocal contacts. Do you have astigmatism? They’ll explain how RGPs may help. 

Next, they’ll talk to you about your daily habits and routine. This is an important part of the discussion because how you wear and care for your contact lenses affects how comfortable they are for you — and helps prevent infections.  

Think about contact lens hygiene — and be honest with your doctor. Do you fall asleep in your contacts? Then you might want to ask your doctor about extended-wear lenses (or switch to daily wear, which can be thrown out at the end of the day). If you’re diligent about cleaning your lenses, on the other hand, you might be a good candidate for monthlies. 

Of course, there’s no one-size-fits-all rule for finding contact lenses — so you’ll need to work with your doctor to find the best pair for you. You may also need to try out more than one type to see what fits comfortably in your eyes. 

How are contact lenses prescribed? 

You’ll need a prescription from an eye doctor to buy contact lenses. They will check your vision, fit you for a prescription, and measure each of your eyes to make sure the lenses fit properly.  

It’s important to know that a contact lens prescription is different from an eyeglass prescription. This is partly because the contact lens will sit directly on your eye, while eyeglass lenses sit slightly away from your eyes. When scheduling your eye exam, let the staff know that you’re interested in talking to the doctor about contact lenses.  

Contact prescriptions usually expire on a yearly basis, so you’ll likely need to have an eye exam each time you buy new lenses. 

 

How should you to take care of your contact lenses?

Wearing your contacts for too long, or wearing old lenses, can cause eye irritation and increase your risk of an infection. Despite these risks, about 6 out of 7 people who wear contacts report not always taking care of them properly, according to a 2017 study by the CDC. 

Here are a few rules to follow: 

Don’t sleep in your contacts. Sleeping in your contacts increases your risk of getting a bacterial eye infection by 6 to 8 times, according to the CDC. Although some contacts — namely, extended- and continuous-wear lenses — are FDA-approved to be worn overnight, sleeping in your lenses still increases the chance that bacteria will get into your eye and cause an infection. 

Don’t try to “stretch” your contacts. Contact lenses are FDA-approved to function for a certain number of days — after that, Dr. Schrepel says, the coating on the lens starts to show signs of wear, and the lens becomes less clear. Plus, older lenses that have passed their expiration date can become dry and uncomfortable, he says. (For more on this, read “Ask an Optometrist: Is It Bad if I Wear My Monthly Contact Lenses for More Than 30 Days?” here.) 

Don’t wear your contacts when you go swimming. Water can harbor many contaminants and organisms, such as an amoeba called Acanthamoeba, which can cause a severe type of eye infection called Acanthamoeba keratitis. Take your contacts out before you go swimming or sit in a hot tub; if you swim in a pool, consider buying prescription goggles.  

“Generally, we don’t want contact lenses stored in water of any kind including tap water and distilled water,” says Dr. Schrepel. “You never know what is in the water and regular water is not ideal for the tear chemistry of the eye.” 

Wash your hands before taking out your lenses. Think about all the people (and pets, and objects) you touch throughout the day — then think about transferring all those germs into your eyes or onto your contact lenses or lens case. You should always wash your hands with soap and water, then dry them with a towel (since water can harbor bacteria) before taking your contacts out of your eyes. 

Clean your contacts every night. It’s not enough to simply dunk the lenses in disinfecting solution (though you certainly should be doing that too). After you take out your contacts, rub them with clean fingers and rinse them in the solution, then leave them to soak overnight in a contact lens case. Gently rubbing the contacts is the best way to remove any deposits and microbes that are lingering on the lenses. 

Don’t top off your solution. If you mix fresh solution in with the solution you’ve been using to store your contacts overnight, you risk an eye infection. That’s because used solution can become contaminated by germs that were on the lenses or the case, causing an invisible layer of biofilm to form, according to the CDC. This biofilm can cause the solution to be less effective at killing the germs on your contacts. 

Clean your contact lens case. When biofilm builds up on your contact lens case, you risk storing your contacts in a solution that can’t effectively kill germs, which increases your risk of an infection. To properly clean your case, rub and rinse it with disinfecting solution, then wipe it with a tissue and allow it to air-dry with the caps off. It’s also a good idea to replace your old case with a new one every three months. 

What are the risks of wearing contact lenses? 

Wearing contact lenses can cause minor or serious problems that range from slight eye irritation to, in rare cases, vision loss.  

Symptoms of eye irritation or eye infection 

If you notice that your eyes feel uncomfortable, take your contacts out right away. Call your eye doctor if you experience symptoms of eye irritation or a possible infection, including: 

• Excess tearing 
• Eye discharge 
• Unusual sensitivity to light 
• Redness 
• Itching, burning, or pain 
• A gritty sensation in the eye 
• Blurry vision 
• Swelling 

Wearing contacts can also cause eye infections or injuries, some of which can result in pain or (rarely) blindness. Below are a few to look out for. If you suspect that you have any of these conditions, call your eye doctor or get emergency medical care right away. 

Keratitis (corneal inflammation) 

Using contact lenses increases the risk of a rare but serious eye condition called corneal inflammation, or keratitis. Untreated keratitis can lead to corneal ulcers, which are open sores that develop on the cornea (the surface of the eye). 

When people don’t properly clean or change their contacts, it becomes more likely that viruses, bacteria, fungi, or amoebas can make their way into the eyes; in severe cases, according to the CDC, this can lead to blindness. 

Corneal abrasions (eye scratches) 

Dirt, dust, and other particles can cause corneal abrasions — i.e., scratches on the surface of the eye (the cornea). There’s also a chance that the scratch can become further infected, leading to a corneal ulcer. 

Conjunctivitis (pink eye) 

Pink eye occurs when the thin layer of tissue that covers the white part of the eye (the conjunctiva) becomes inflamed. Pink eye is caused by bacteria, usually staphylococcal or streptococcal bacteria, according to the American Optometric Association. 

In particular, giant papillary conjunctivitis — an allergic form of pink eye — is caused when a foreign object stays in the eye over a longer period of time. People who wear hard contact lenses, or those who wear soft contacts for too long, are at an increased risk of this type of pink eye. 

The good news: Carefully following the wear-and-care tips outlined above can minimize the risk. 

Additional reading:

Dailies vs. Monthlies: Which Contact Lens Is Best for You?

3 Questions Your Eye Doctor Wants You to Answer Before Buying Contact Lenses

Care Tips for Contact Lenses

Have Astigmatism? You Have Contact Lens Options (More Than You Think)

Ask an Optometrist: Is it bad if I wear my monthly contact lenses for more than 30 days?

The Pros and Cons of Contact Lenses for Kids Who Play Sports

6 Signs Your Kid Is Ready for a Contact Lens Eye Exam

5 Fast Fixes for Your Contact Lens Mishaps

Wearing Contact Lenses and Reading Glasses? You Have Better Options

Wearing Makeup With Contact Lenses

Color Contact Lenses: 4 Essential Rules

I Slept in Contacts. Now What?