Wearing Contacts While Sleeping: Is It Safe?

Sleeping with contact lenses in is not recommended. It can cause eye infections, lens displacement, and dry eyes. Even a short nap with contact lenses in can lead to these issues. Contact lenses reduce the amount of oxygen that reaches the cornea, causing the eyes to become swollen or inflamed, leading to discomfort and even pain. This can also cause permanent vision loss.

Overnight contacts can cause corneal inflammation and infection

Contact lenses are generally considered safe, with about 45 million Americans wearing them. However, they can cause serious eye health issues if not properly cared for or worn for too long, especially overnight.

Corneal Inflammation and Infections

The cornea is the clear, outer layer of the eye. It has no blood vessels, so it needs access to oxygen from the air. Contact lenses can restrict oxygen flow to the cornea, damaging the surface cells (epithelial cells). Repeated oxygen deprivation can cause these cells to deteriorate and die.

When the cornea doesn't receive enough oxygen, it becomes vulnerable to bacteria, particularly when contact lenses are left in overnight. Soft contacts, in particular, can retain water, as well as debris and bacteria that enter the eye during the day. If lenses are not cleaned properly, this creates an environment for bacteria to thrive.

Bacteria thrive in warm, dark environments—the exact conditions created when you sleep with your contacts in. This is why sleeping with contacts in, even occasionally, can cause a corneal ulcer (bacterial keratitis), a painful defect on the cornea's surface caused by bacterial infection.

Other Types of Keratitis

In addition to bacterial keratitis, other types of keratitis include:

• Parasitic/amebic keratitis, caused by an amoeba called Acanthamoeba, which can be found in natural bodies of water, tap water, and hot tubs.
• HSV (Herpes Simplex Virus) keratitis.

Symptoms and Treatment of Keratitis

Symptoms of microbial keratitis include worsening pain in or around the eyes, sudden blurry vision, and unusually watery eyes or discharge. If you experience any of these symptoms, remove your contacts and contact your eye doctor immediately.

Microbial keratitis can usually be treated with aggressive antibiotics, but whether it causes long-term vision issues depends on the situation. In severe cases, it can lead to blindness or the need for a corneal transplant.

Lack of oxygen to the cornea

Contact lenses are typically designed for daily wear and should be removed before sleeping. Sleeping in your contact lenses can have side effects and increases the risk of eye infections by six to eight times.

The cornea has no blood supply of its own and gets oxygen only from tears and directly from the atmosphere. When a person sleeps in their contact lenses, the oxygen supply to the cornea is reduced, causing it to swell. This is known as corneal hypoxia. The cornea starts to accumulate lactic acid, which pulls water towards it, causing edema. While mild corneal edema is common when sleeping, even with the lenses removed, contact lenses can make this worse.

If the swelling and hypoxia become more than mild, symptoms such as hazy or blurry vision can occur and develop into more severe problems such as the formation of cysts.

Extended-wear contact lenses are designed for repeat wear, including overnight wear. However, it is still beneficial to give your eyes an oxygen break by removing the lenses.

Increased risk of eye infections

Sleeping in your contact lenses increases your risk of getting an eye infection. Contact lenses can trap bacteria against your eye, creating an optimal environment for bacteria to enter your eye. The warmth and moisture provided by your eyelids when you're asleep, combined with the reduced oxygen supply to your eyes, create ideal conditions for bacterial and viral infections to grow.

Contact lens wearers are at risk of developing microbial keratitis, an infection of the cornea, which is the clear layer protecting the coloured part of your eye. The risk of microbial keratitis is over five times higher when you wear your contact lenses overnight. This risk occurs regardless of your lens type—soft, hard, decorative, or prescription.

Acanthamoeba keratitis is another type of infection caused by a tiny, single-celled organism called Acanthamoeba, which can be found in natural bodies of water, soil, tap water, heating and air conditioning systems, and hot tubs. Wearing contact lenses puts people at risk for Acanthamoeba keratitis, with 85% of those who experience this inflammation being contact lens wearers.

Sleeping in your contact lenses can also lead to fungal keratitis, a corneal inflammation caused by a fungal infection. Types of fungi often behind fungal keratitis include those from the Fusarium, Aspergillus, and Candida species. This type of infection is more common in tropical areas but can occur in any climate.

Even if you don't develop a full-blown infection, sleeping in your contact lenses can still cause irritation and redness in your eyes. This is because the lenses can absorb the natural moisture in your eyes, making your eyes feel dry and uncomfortable. When you sleep in your contact lenses, the problem is exacerbated due to the lack of airflow and reduced tear production during sleep.

In summary, sleeping in your contact lenses significantly increases your risk of developing eye infections, which can have serious consequences for your eye health and vision. It is essential to remove your contact lenses before sleeping and to practice good contact lens hygiene to maintain healthy eyes.

Dry eyes

Dry eye is a common problem for contact lens wearers. The condition can cause the lenses themselves to dry out, and the lenses can also absorb moisture from the eye. This can lead to discomfort and irritation.

Dry eye syndrome is an eye condition that causes symptoms such as burning, itching, stinging, and a gritty feeling in the eye. It can be caused by several factors, including genetics, aging, and medications. For contact lens wearers, dry eye can be especially problematic as the eye requires natural moisture for a comfortable, flexible fit.

There are several ways to manage dry eye symptoms:

• Natural remedies such as avoiding irritants, using a warm compress, limiting screen time, and using a humidifier.
• Over-the-counter or prescription eye drops, known as artificial tears, can provide temporary relief.
• Tear duct plugs can help prevent moisture from draining too quickly.
• Surgery can be an option to prevent tear drainage.
• Switching to a different type of contact lens or modifying your hygiene routine may be necessary.

When it comes to contact lenses, there are several factors to consider to reduce dry eye symptoms:

• Lens type: Soft lenses are typically recommended for dry eyes as they are made of flexible plastic that allows oxygen to pass through to the eye. Hard lenses, or rigid gas permeable (RGP) lenses, are made of stronger material and may be a better choice for patients with dry eyes as they don't contain water.
• Disposable vs. reusable: Single-use, disposable lenses are generally recommended for dry eyes as they are less likely to cause protein deposits that can lead to irritation and inflammation. However, some people may benefit from reusable lenses due to their lower water content.
• Water content: Lenses with low water content tend to dry out more slowly and need less water to stay hydrated.
• Replacement schedule: Changing lenses frequently can help prevent deposits and protein buildup, which can cause dry eye symptoms. Daily disposable lenses are usually recommended for dry eye sufferers.
• Proper fitting: Poorly fitted lenses can cause inflammation and irritation, leading to dry eye symptoms.
• Contact solution: Some solutions may contain preservatives that irritate the eyes and cause dryness. Talk to your optometrist about the best solution for your lenses.

It is important to note that even with proper lens care and hygiene, dry eye symptoms may still occur. In such cases, it is best to consult an eye doctor for further advice and treatment options.

Potential permanent damage

Potential for Permanent Damage

Although rare, severe complications can occur from repeatedly or prolonged sleeping in contact lenses. Bacterial infections can scar the cornea and may require surgery, including a corneal transplant. In some cases, this can even result in permanent vision impairment or complete vision loss.

Anyone experiencing sudden eye pain, a change in vision, or light sensitivity after sleeping in lenses should seek emergency medical care to prevent blindness.

Sleeping in lenses is never worth risking your sight. If you accidentally sleep in your contact lenses, it is important to remove them immediately upon waking up and monitor your eyes for any signs of discomfort or infection.

Corneal Infections

The risk of microbial keratitis, a form of corneal inflammation caused by infection, is over five times higher when sleeping in contact lenses. This risk occurs regardless of your lens type, be it soft, hard, decorative, or prescription.

Bacterial keratitis, or a cornea inflamed due to bacterial infection, can cause a person to lose part or all of their vision if not properly treated. Acanthamoeba keratitis, an inflammation of the cornea due to an infection caused by amoeba, can also lead to vision loss or blindness.

Corneal Ulcers

Corneal ulcers develop when the eyes are deprived of oxygen while closed during sleep. Contact lenses further restrict airflow, causing injury to corneal cells. This damage allows infections to set in, resulting in painful corneal ulcers.

Hypoxia

Corneal hypoxia is when the cornea does not receive enough oxygen. This can cause symptoms such as redness, irritation, and discomfort.

Frequently asked questions