Contact lenses are medical devices that require careful use to maintain eye health. While they offer a convenient alternative to eyeglasses, sleeping in them is widely discouraged due to various potential risks. Understanding these risks helps in making informed decisions for eye health.
Immediate and Common Eye Reactions
Waking up after sleeping in contact lenses often results in eye discomfort. Dry eyes are a common immediate reaction, as lenses absorb moisture and tear production decreases during sleep.
This dryness frequently leads to redness, irritation, and a scratchy or gritty feeling. Many also report a foreign object sensation and blurry vision upon waking.
These effects are usually transient, improving quickly once lenses are removed.
Serious Ocular Complications
Beyond immediate discomfort, sleeping in contact lenses can lead to serious, sight-threatening conditions.
Corneal ulcers are open sores on the cornea. These can stem from bacterial, fungal, or amoebic infections, causing pain and scarring that impairs vision, sometimes necessitating a corneal transplant.
Microbial keratitis, an inflammation caused by microorganisms, is another severe complication. Acanthamoeba keratitis is particularly concerning due to its treatment resistance and high potential for permanent vision loss. Studies indicate sleeping in contact lenses increases microbial keratitis risk by five to eight times.
Corneal neovascularization involves abnormal blood vessel growth into the cornea, a clear structure that should be free of blood vessels. This obstructs vision and often results from prolonged oxygen deprivation. Untreated, it can lead to lipid deposits, hemorrhage, and scarring, further compromising vision.
Underlying Biological Mechanisms
Several physiological factors contribute to the adverse effects of sleeping in contact lenses.
The cornea, the transparent front part of the eye, primarily receives oxygen directly from the atmosphere. When eyelids are closed during sleep, the oxygen supply to the cornea is already reduced. Wearing a contact lens adds an additional barrier, significantly cutting off oxygen, leading to corneal hypoxia. This oxygen deprivation can cause the cornea to swell and become more susceptible to damage and infection.
The warm, moist environment created under a contact lens, especially with closed eyelids, provides an ideal breeding ground for bacteria and other microorganisms. Lenses can trap these microbes against the corneal surface, preventing the natural flushing action of tears. This reduced tear exchange allows debris and microorganisms to accumulate, increasing infection likelihood. Additionally, the lens itself can cause minor abrasions or irritation on the corneal surface, creating entry points for pathogens and making the eye more vulnerable.
Preventative Measures and Immediate Actions
To prevent complications, avoid sleeping in contact lenses unless specifically designed for extended wear and approved by an eye care professional. Even then, many specialists advise against overnight use due to increased infection risk.
Proper contact lens hygiene is essential, including thoroughly washing hands before handling lenses and using fresh, sterile solution daily for cleaning and storage. Never use tap water or saliva, as they introduce harmful microorganisms.
If you accidentally fall asleep with lenses in, do not remove them immediately if dry or stuck. Gently massage eyes and apply lubricating eye drops or saline to rehydrate them for easier removal.
After removal, wear glasses for at least a day to allow eye recovery and oxygen replenishment. Seek immediate professional medical attention if symptoms like persistent redness, pain, increased light sensitivity, or vision changes occur or worsen.