Sleeping in contact lenses significantly increases the risk of developing an eye infection, including a form of pink eye. Contact lenses are medical devices, and wearing them overnight is a leading cause of preventable eye infections and complications. This misuse can raise the risk of a serious eye infection by six to eight times compared to those who follow proper wear schedules. The eye’s delicate environment is compromised when a lens remains on the cornea while the eyelids are closed during sleep.
Understanding Conjunctivitis (Pink Eye)
Conjunctivitis, commonly known as pink eye, is an inflammation of the conjunctiva, the thin membrane lining the inner eyelid and covering the white part of the eyeball. This condition results in noticeable redness, irritation, and often discharge from the eye. The three main types of conjunctivitis are viral, bacterial, and allergic.
Viral conjunctivitis is the most common form, often accompanying a cold or upper respiratory infection, and is highly contagious. Bacterial conjunctivitis is caused by bacteria like Staphylococcus or Streptococcus, leading to a thick, sticky yellow or greenish discharge. Allergic conjunctivitis is not contagious and is triggered by allergens like pollen or pet dander.
The bacterial form is most directly linked to poor lens hygiene and sleeping in contacts. The lens acts as a breeding ground, trapping pathogens against the surface of the eye. This can lead to microbial keratitis, a severe infection of the cornea itself.
The Specific Risk of Sleeping in Contacts
Sleeping while wearing contact lenses fundamentally changes the eye’s environment, favoring bacterial growth and infection. The cornea needs a constant supply of oxygen, primarily received from the air when the eyes are open. When the eyelids are closed, the cornea receives oxygen only from the blood vessels in the conjunctiva.
The presence of a contact lens creates a further barrier, severely restricting the oxygen supply to the cornea, a condition called corneal hypoxia. This lack of oxygen weakens the eye’s natural defenses against invading bacteria. Oxygen deprivation can lead to swelling and compromise the integrity of the corneal surface.
A contact lens worn overnight also acts like a physical shield, trapping debris, microorganisms, and protein deposits against the corneal surface. Bacteria from the lens or tear film are held in close proximity to the vulnerable cornea for hours. This concentrated exposure significantly increases the odds of a pathogen penetrating the weakened corneal tissue and causing a severe infection.
Furthermore, the lens can cause micro-trauma to the corneal surface, especially when the eye is dry during sleep. The slight friction between the lens and the cornea can create tiny, invisible scratches or abrasions. These microscopic breaks in the corneal epithelium provide an easy entry point for bacteria to cause a serious infection, such as microbial keratitis, which can lead to permanent vision loss if untreated. The combination of reduced oxygen, trapped bacteria, and physical damage makes sleeping in lenses a high-risk behavior for eye health.
Immediate Steps and Safe Contact Lens Practices
If you wake up with symptoms of pink eye or a possible eye infection, such as redness, pain, discharge, or increased light sensitivity, remove your contact lenses immediately. Switch to wearing glasses and do not attempt to reinsert the contacts, even if only one eye seems affected. Immediately contact an eye care professional, as a severe infection requires prompt diagnosis and treatment, often with prescription antibiotic drops.
Never attempt to treat the infection yourself with old eye drops, and do not rub your eyes, as this can spread the infection. If you use reusable lenses, discard the pair you were wearing when symptoms began, along with the lens solution in the case. The lens case itself should be thoroughly cleaned and replaced, as both can harbor infectious agents.
To prevent future infections, strict adherence to safe contact lens practices is necessary:
- Never sleep in your contact lenses, even for a short nap, unless specifically approved by your eye doctor for extended wear.
- Always wash your hands thoroughly with soap and water and dry them completely with a clean towel before handling your lenses.
- Use only fresh, sterile contact lens solution to clean and store your lenses; never “top off” old solution or use tap water.
- Always follow the prescribed replacement schedule for your lenses to avoid protein and microbial buildup.
- Replace your contact lens storage case at least once every three months to prevent contamination.
- Wearing daily disposable lenses, which are thrown away after a single use, is often recommended as the safest option to minimize infection risk.