Sleeping In Contacts: A Safe Practice?

Sleeping in your contact lenses, even if they are daily disposable ones, can have adverse effects on your eyes. It is not safe to sleep with your contacts in, even if it's just a nap. While it may seem like a harmless mistake, doing so can increase the risk of eye infections, such as microbial keratitis, and lead to corneal damage, surgery, and even loss of vision. Contact lenses trap dirt and debris, blocking oxygen from flowing freely to the eye. This can cause irritation, redness, dryness, and discomfort. It is best to always remove contact lenses before sleeping and give your eyes a break.

Oxygen deprivation

During sleep, the cornea receives nourishment from hydration in the form of gelatinous fluid and tears. Contact lenses act as a blockade between the cornea and the eyelids, depriving the eyes of oxygen. This creates an ideal environment for bacteria and other potentially harmful substances to build up, leading to severe damage.

Symptoms of oxygen deprivation in the eyes include blurred vision, burning, excessive tearing, and a scratchy feeling, as if there is sand in the eye. Mild cases of corneal hypoxia typically result in swelling of the epithelial layer of the cornea and temporary blurred vision. However, more severe cases can lead to the death of epithelial cells, causing permanent damage.

Sleeping in contact lenses, even those approved for overnight or extended wear, significantly increases the risk of eye infections. The longer the lenses remain in the eyes, the more opportunity there is for bacteria to grow unimpeded. This can lead to infections such as microbial keratitis, bacterial keratitis, Acanthamoeba keratitis, and fungal keratitis, all of which can cause vision loss or even blindness.

To prevent oxygen deprivation and reduce the risk of eye infections, it is crucial to follow proper contact lens care instructions. This includes removing contacts before sleeping, cleaning and disinfecting lenses as directed, and practicing good hygiene when handling lenses.

Eye infections

Sleeping in your contact lenses increases your risk of eye infections by six to eight times. This is because the cornea needs oxygen to function healthily, and contact lenses significantly reduce the amount of oxygen that reaches the eye. When the cornea does not get enough oxygen, a state called hypoxia, its ability to fight bacteria is impaired.

Types of Eye Infections

Bacterial Keratitis

Bacterial keratitis is an infection of the cornea, which can be caused by different types of bacteria, such as Pseudomonas aeruginosa and Staphylococcus aureus. These bacteria can be introduced to the eye via fingers when putting contacts in or taking them out, or from lenses or storage cases that have not been properly cleaned. Rinsing lenses in water can also increase the risk of bacterial keratitis.

Acanthamoeba Keratitis

Acanthamoeba keratitis is an inflammation of the cornea caused by an amoeba called Acanthamoeba. This organism can be found in natural bodies of water, soil, tap water, heating and air conditioning systems, and hot tubs. Poor contact lens hygiene, such as swimming or showering while wearing contacts, increases the risk of this type of infection.

Fungal Keratitis

Fungal keratitis is caused by a fungal infection of the cornea. It is more common in tropical areas but can occur in any climate. It is usually treated with antifungal medicine, but severe cases may require surgery or a corneal transplant. Contact lens wear is a risk factor for this type of infection.

Signs of Eye Infection

• Eye pain or discomfort
• Excessive tearing
• Sensitivity to light
• Itchy or burning eyes
• Redness
• Excessive watering or discharge

Preventing Eye Infections

To prevent eye infections, it is important to practice good contact lens hygiene. This includes:

• Cleaning and disinfecting lenses according to the instructions.
• Discarding leftover contact lens solution and using fresh solution each time.
• Avoiding exposing lenses to water, saliva, or any other liquid.
• Replacing the lens storage case every three months or as directed by an eye doctor.
• Visiting the eye doctor annually and always using a prescription for contact lenses.

Corneal damage

Sleeping in your contact lenses can have serious consequences for your eye health, particularly when it comes to the cornea. The cornea is the clear layer protecting the coloured part of your eye. It relies on oxygen from the atmosphere, which dissolves in the tear film that coats your eye.

When you sleep in your contact lenses, you are depriving your eyes of oxygen. This can cause a buildup of blood vessels on the cornea, known as corneal neovascularization. This can change the shape of your cornea and even result in you no longer being able to wear contact lenses.

The risk of a corneal infection is also increased six to eight times when you sleep in your contact lenses. Infections can cause permanent corneal damage and vision loss. Types of corneal infections include:

• Bacterial keratitis, which can be caused by bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus, found in soil, water, and the human body.
• Acanthamoeba keratitis, caused by a tiny, single-celled organism called Acanthamoeba, found in natural bodies of water, soil, tap water, heating and air conditioning systems, and hot tubs.
• Fungal keratitis, caused by types of fungi including Fusarium, Aspergillus, and Candida species.

Sleeping in your contact lenses can also lead to corneal ulcers, which are open sores on the cornea that can cause significant vision impairment or even permanent vision loss if not treated quickly.

Vision loss

Wearing contact lenses while sleeping can lead to vision loss in several ways. Firstly, contacts block oxygen from reaching the eye, and this oxygen deprivation can lead to a buildup of blood vessels on the cornea, a condition known as corneal neovascularization. This condition can cause permanent vision damage.

Secondly, contacts can increase the risk of eye infections, such as bacterial keratitis, which can cause partial or complete vision loss if not properly treated. Acanthamoeba keratitis, another type of infection caused by amoeba, can also lead to blindness.

Fungal keratitis, caused by a fungal infection, is yet another potential complication of sleeping in contact lenses. This condition can also result in vision loss or blindness if left untreated.

Furthermore, wearing contacts overnight can lead to corneal ulcers, which are open sores on the cornea. These ulcers can also cause permanent vision damage.

In addition to these specific conditions, sleeping in contacts can also cause general eye damage and irritation, which can affect vision. This damage can be irreversible, and it's important to note that eye professionals can usually tell if someone has been sleeping in their contacts, as the cornea will appear damaged under magnification.

Lens displacement

Contact lenses are designed to be worn during the day and then taken out at night. Sleeping in your contacts can increase the risk of eye infections and corneal damage, which can lead to vision loss or even blindness. It is important to give your eyes a break and let them breathe by taking out your contacts before you sleep.

Even a short nap with contact lenses in can lead to these issues. If you accidentally fall asleep with your contacts in, it is recommended to gently massage your eyes to get some moisture flowing, then try to nudge the lenses out without tugging at them. If they are stuck, use a couple of drops of contact solution and blink a few times before trying again. After removing the lenses, it is best to give your eyes a break from contacts for a whole day if possible.

While some contacts are approved for overnight wear, even these extended-wear contacts are not recommended by experts due to the risk of eye infections and other complications.

Frequently asked questions