Sleeping With Contact Lenses: Risks And Dangers

Sleeping with contact lenses in your eyes is not safe and can lead to several eye-related issues. It can cause infections, eye damage, and discomfort. Contact lenses reduce the amount of oxygen and moisture that can reach your eyes, creating an environment where bacteria can thrive. This increases the risk of eye infections such as microbial keratitis, which can lead to vision loss and permanent corneal damage. Additionally, the lack of oxygen can cause swelling in the cornea, allowing bacteria to enter and potentially causing infections such as bacterial keratitis, acanthamoeba keratitis, and fungal keratitis. Even a short nap with contact lenses can increase the risk of eye irritation and infection. It is recommended to remove contact lenses before sleeping and practice good contact lens hygiene to maintain eye health.

Risk of eye infection

Sleeping in your contact lenses can have serious consequences for your eye health and vision. The Centers for Disease Control and Prevention (CDC) reports that sleeping in your contact lenses makes you six to eight times more likely to get an eye infection. This is because your cornea needs a healthy supply of oxygen and hydration to fight off bacteria and other microbes effectively.

Microbial Keratitis

Microbial keratitis is a common eye infection that can be caused by sleeping in your contact lenses. It is an inflammation and infection of the cornea, the protective outer layer of your eye. Microbial keratitis can be caused by bacteria, viruses, fungi, or parasites, and it can have serious complications if left untreated. One study showed that wearing contact lenses overnight increased the risk of microbial keratitis by more than five times, regardless of the type of lens used.

Bacterial Keratitis

Bacterial keratitis is a type of corneal infection caused by bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus, which can be found in soil, water, and on your body. Contact lens wear increases your risk of this type of infection, especially if you wear your lenses overnight. Bacterial keratitis can occur when bacteria are introduced to your lenses through improper handling or a contaminated lens case. Rinsing your lenses in water instead of contact solution can also increase your risk of this infection.

Acanthamoeba Keratitis

Acanthamoeba keratitis is an infection of the cornea caused by a type of amoeba called Acanthamoeba, which can be found in natural bodies of water, soil, tap water, and even heating and air conditioning systems. Poor contact lens hygiene, such as swimming or showering while wearing your lenses, increases your risk of this infection. Sleeping in your lenses overnight can also make you more susceptible to Acanthamoeba keratitis. This type of infection can lead to permanent vision loss or blindness.

Fungal Keratitis

Fungal keratitis is another type of corneal infection that can be caused by sleeping in your contact lenses. It is most common in tropical areas but can occur in any climate. It is typically caused by fungi from the Fusarium, Aspergillus, and Candida species. If left untreated, fungal keratitis can lead to vision loss or blindness and may require surgery or a corneal transplant.

Corneal Ulcer

A corneal ulcer is a serious complication that can result from sleeping in your contact lenses. It is an eruption on the cornea caused by an infection, which can lead to blindness. Symptoms of a corneal ulcer include vision changes, eye redness, eye discomfort or pain, and excessive tearing. If the infection is caused by an aggressive microbe, it can permanently damage the cornea and require a corneal transplant.

Conjunctivitis

Conjunctivitis, or pink eye, is another eye condition that you are at risk of developing if you sleep in your contact lenses. While it is usually not as serious as the other infections mentioned, it can still cause significant discomfort and require medical treatment.

Corneal Hypoxia

Corneal hypoxia is a condition that occurs when the cornea does not receive enough oxygen. Sleeping in your contact lenses can contribute to this condition, as the lenses can block oxygen from reaching the cornea. This can lead to damage to the epithelial cells of the cornea, which can die if they are deprived of oxygen for too long.

Other Risks

In addition to the risk of eye infections, sleeping in your contact lenses can also lead to general inflammation, irritation, and dryness of the eyes. Debris trapped under the lenses can further damage your eyes. Additionally, there is a risk of developing "corneal neovascularization," which occurs due to a lack of oxygen to the eye. This condition may result in you no longer being able to wear contact lenses and having to switch to glasses or hard contact lenses.

Lack of oxygen to the cornea

The cornea, the outermost layer of the eye, does not have blood vessels (except near its edges) and relies on the air to obtain the oxygen it requires for metabolism. When contact lenses are worn for too long, they cut off the oxygen supply to the cornea, resulting in a condition known as corneal hypoxia.

During the day, the cornea can usually get enough oxygen, even with contact lenses in, but at night, the decrease in oxygen becomes more severe. The longer you sleep in your contacts, the more you are depriving your eyes of oxygen. This lack of oxygen can cause the cornea to start to swell as it accumulates lactic acid, which pulls water towards it, causing edema. While the initial symptoms of corneal hypoxia may seem mild, there is also the potential for much more serious problems, including the development of corneal cysts and the death of epithelial cells, both of which can compromise your vision.

Symptoms of corneal hypoxia include blurred vision, burning, excessive tearing, and a scratchy feeling, almost like there is sand in the eye. If you notice any of these symptoms, it is important to see an eye doctor right away.

To avoid corneal hypoxia, do not wear contact lenses overnight or for longer than recommended. If you start to notice any signs of corneal hypoxia, remove your lenses to allow the issue to resolve. You may also want to switch to gas-permeable contact lenses, which are made from a material that enables oxygen to pass through them and reach the surface of the eyes, keeping the cornea oxygenated.

Stagnation of the tear film

The tear film is a complex fluid with many components that work together to deliver several functions of vision, health, and comfort related to the anterior eye. When a contact lens is placed on the eye, the tear film is split into two distinct layers: the pre-lens tear film and the post-lens tear film. The tear film is crucial for maintaining a healthy and comfortable ocular surface.

The stagnation of the tear film occurs when contact lenses are worn overnight. During sleep, the eye is closed and not blinking, which inhibits the normal "refreshing" of the tear film through the addition of new fluid and the clearing out of old fluid. This can lead to a build-up of germs and debris, increasing the risk of eye infections and other eye conditions such as microbial keratitis, conjunctivitis, corneal ulcers, and corneal hypoxia.

The tear film plays a critical role in protecting the eye from bacteria and debris. When contact lenses are worn overnight, the tear film is unable to perform its protective function effectively, increasing the risk of eye infections. Additionally, the tear film can become stagnant, leading to a build-up of germs and debris that can cause further damage to the eye.

The tear film is also essential for maintaining ocular health and comfort. When the tear film becomes stagnant, it can lead to dryness, soreness, and redness of the eyes. This can cause discomfort and irritation, especially if there is any debris trapped under the contact lenses.

Furthermore, the tear film has a role in maintaining the hydration and lubrication of the ocular surface. When the tear film becomes stagnant, it can lead to a decrease in hydration and lubrication, causing the eyes to feel dry and uncomfortable.

In conclusion, stagnation of the tear film due to overnight contact lens wear can increase the risk of eye infections, cause eye irritation and discomfort, and affect the hydration and lubrication of the ocular surface. It is important to remove contact lenses before sleeping to maintain eye health and comfort.

Interaction with the surface of the eye

Prolonged contact lens wear can affect the physical structure of your eye's surface. The ocular surface environment is extraordinarily sensitive and can change shape if subjected to the pressure of contact lenses for too long. Researchers are investigating how these surface interactions can hasten infection.

Your lenses might rub uncomfortably against the cornea as you sleep, increasing the chance of scratches and irritation. This can lead to a condition called CLARE (Contact Lens Acute Red Eye), which is characterised by eye pain, redness, and light sensitivity.

Another possible complication is corneal neovascularization, which occurs due to a lack of oxygen to the eye. If the vessels grow too much, doctors may advise against wearing contact lenses anymore. A similar condition caused by a lack of oxygen to the eye is called corneal microscysts, or hypoxia.

Additionally, sleeping in your contact lenses can lead to corneal ulcers, which are eruptions on the cornea caused by infection. This is considered one of the biggest complications of sleeping in contact lenses, as it can lead to blindness and may require a corneal transplant.

Exposure to microbes via contamination

Contact lenses can transfer microbes to your eyes from other sources, including your hands or your lens case. When you sleep with your contact lenses in, you give these microbes a warm, dark, stagnant environment in which to thrive.

Contact lenses sit over the tear film that covers the surface of your eye, inhibiting the tear exchange that usually takes place when you blink. Germs are not washed away and instead have time to spread. The longer you sleep in your contacts, the more opportunity you give them to cause infection.

Additionally, the surface of your eye is extraordinarily sensitive. Studies show that the ocular surface environment can even change shape if subjected to the pressure of contact lenses for too long. Researchers are investigating how these surface interactions can hasten infection.

Furthermore, your lenses might rub uncomfortably against the cornea as you sleep, increasing the chance of scratches and irritation.

To avoid exposure to microbes via contamination, it is important to wash your hands, let your contact case air dry during the day, regularly clean your contact case, always use fresh contact solution for storage, and clean your contact lenses thoroughly with each use.

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