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When you're sound asleep, you're not prompted to blink. That means your eyes are not nourished by a constant flood of tears, and your lids aren't pushing bacterial invaders out of your eyes. (Learn more) Traditional contact lenses work like a cap on your eyes, blocking vital tissues from getting the nourishment they need at night. Extended-wear contacts are designed to allow oxygen to flow in and out, so you can wear them through the night. (Learn more)
Unfortunately, even extended-wear contact lenses can interfere with the health of your eyes as you sleep. They can block tear exchange, trap bacteria on the surface of the eye, and more. (Learn more)
Wearing contacts at night dramatically increases your risk of corneal infections, and the habit can lead to other eye health issues that can block you from ever wearing contact lenses again. (Learn more)
Your doctor can help if you do get an infection from nighttime contact lens use, and you can take steps at home to lower your risk of infections. Your best course of action is to stop wearing any kind of contact lens as you sleep. (Learn more)
Your Eyes Need Protection During Sleep
Throughout the day, your eyes are bathed with the nourishment of tears. Each blink delivers a mixture of moisture and vitamins to the surface of the eye, and the movement of the lids helps to brush away foreign invaders that might harm your eyes. The National Keratoconus Foundation reports that blinking plays a key role in preventing infection and keeping the eye healthy.
During the night, muscles relax and the lids close. This means you're not blinking throughout the night. Your eyes are still bathed in tears, but the lack of blinking can lead to slight drying of the surface of the eye, especially in those who sleep with their eyelids partially open.
The lids can keep the surface of the eye from fully accessing oxygen in the air, and that can also lead to eye vulnerability throughout the night. Oxygen helps your eyes to fight off infection, and without it, they are vulnerable.
The human body is adept at dealing with routine, repeating challenges. As a result, most of us don’t notice the trauma our eyes have been through during the night. We may awaken with eyes that feel a little dry or gritty, but a few blinks can seem to set things right.
Wearing contact lenses can add even more trauma to those sensitive eyes, however. That could lead to damage you can both see and feel.
Contact Designers Hope to Help
Traditional contact lenses are made of hard plastic, and they work like a cap on the surface of the eye. These hard lenses offer crisp vision, and after a period of adjustment, people may not notice that they're wearing lenses at all. But these rigid lenses can block the entry of oxygen to the eyes, and they're not at all appropriate for around-the-clock wear. Your doctor and the packaging may remind you of that fact.
Extended-wear contacts are different. According to the U.S. Food and Drug Administration, lenses like this are typically soft, although there are some rigid extended-wear lenses available. These lenses are made to wear both day and night, from one to six nights or up to 30 days.
In theory, these lenses have been made to allow you to wear them all the time, even at night, with no worry. But eye health professionals worry about nighttime use, no matter what kind of lens you might choose to use.
How Your Contacts Interfere With Night Eye Health
The American Academy of Ophthalmology reports that extended-wear contacts are designed for constant use, but the organization states that "fewer" eye doctors recommend these types of lenses, as they increase the risk of a serious eye infection.
As mentioned, the impulse to blink is absent at night, and that can allow bacterial cells to latch onto the eye and colonies to grow through the night. In addition, closed eyes have access to a smaller amount of oxygen, which is used in infection control. Adding contact lenses to the mix can make the situation worse.
An eye doctor interviewed by Health Day explains that contact lenses can trap bacteria on the surface of the eye, right beneath the cap of the lens. Bacteria can grow in this protected space throughout the night, with nothing to interfere with the growth.
In addition, contact lenses can trap tear byproducts and metabolic byproducts, according to research published in the Journal of Optometry. This suggests that contacts work less like a sieve and more like a cap, and those byproducts may include bacterial cells that could grow into colonies. Without a free exchange of fluid through the contact, this is a problem that could grow in severity.
Nighttime Wear Can Cause Major Problems
The risks involved with wearing contacts at night are clear. As the Centers for Disease Control and Prevention point out, sleeping in contact lenses can up the risk of eye infections sixfold to eightfold. Serious infections like this can cause:
- Corneal scarring.
- Corneal rupture.
- Permanent vision loss.
- The need for a corneal transplant.
Infections like this can come on even if you wear your contacts just one time through the night. You don't need to wear them repeatedly to be at risk of a serious infection. There are also other risks associated with repeatedly sleeping in contacts.
As you continue to sleep with your contacts on, your eyes can begin to adjust in ways that can make ongoing contact use difficult. For example, according to the National Sleep Foundation, you can develop an overgrowth of corneal blood vessels, which can change the shape of the eye. That can make fitting contacts difficult. Recurrent contact lens use at night can irritate eyelids, causing bumps that drag on contacts. That can make wearing contacts tough unless the bumps go away.
Get Help From a Doctor
If you develop an infection due to contact use, your doctor can help. The Cleveland Clinic recommends bringing your contact in your contact case when you visit your doctor for help. Your doctor may choose to culture the contact to determine just what kind of bacteria has grown in your eye, so the right antibiotics can be used to help you.
The Centers for Disease Control and Prevention suggests that there are other steps you can take to reduce the risk of infections with contact lenses.
- Dispose of lenses as recommended instead of wearing them for longer in order to save money.
- Use a proper case to store your contacts.
- Replace your contact lens case regularly.
- Use lens solution, not tap water, on your lenses.
While these steps can help to reduce your risk of infection, the best step you can take is to avoid sleeping in your contacts. The few minutes you'll spend taking your lenses out are worth the suffering you might avoid.
If you're struggling with life with contact lenses, we can help. There are surgical procedures that can help to amend your vision, so you won't need to wear contacts all the time. If surgery isn't right for you, we can help you find contacts that are comfortable during the day and easy to take out at night. Contact us to find out more and to make an appointment with one of our eye health professionals.
The Patient Experience
Science and Art of Blinking. National Keratoconus Foundation.
Types of Contact Lenses. (January 2018). U.S. Food and Drug Administration.
Contact Lens Types. (September 2018). American Academy of Ophthalmology.
Sleep in Your Contacts, Risk Serious Eye Damage: CDC. (August 2018). Health Day.
Tear Exchange and Contact Lenses: A Review. (January 2015). Journal of Optometry.
Corneal Infections Associated with Sleeping in Contact Lenses—Six Cases, United States, 2016-2018. (August 2018). Centers for Disease Control and Prevention.
Sleeping With Your Contacts In: Is it Bad? National Sleep Foundation.
What Does Sleeping in Contact Lenses Do to Your Eyes? (November 2017). Cleveland Clinic.
Contact Lens Wearer Demographics and Risk Behaviors for Contact Lens-Related Eye Infections—United States, 2014. (August 2015). Centers for Disease Control and Prevention.