What your Doctor Wants You to Know About Extended Wear Contacts
Extended wear contacts
Extended wear contacts are officially tested and approved by the FDA for over-night wear. Some patients even wear them for several days/nights in a row. Most extended wear contacts are FDA approved for up to six nights and seven days. While it is strongly discouraged, some patients just put them in and leave them until their eyes hurt.
Two examples of extended wear contacts are the Biofinity by Coopervision and Air Optix Night & Day by Alcon. Some patients sleep in contacts that have not been tested and approved as “safe” for overnight wear. This is even riskier for your eye health. Why risk it?
Long term wear of contacts and comfort
Having contact lenses in your eyes disrupts the normal flow of oxygen to the cornea. When the delicate balance of homeostasis is disrupted, discomfort or dryness often follow.
“All things in moderation” is a good axiom for contact lens wearers to follow. The doctors at Cannon EyeCare encourage all of our patients to avoid Contact Lens Over- Wear (CLOW) by taking the lenses out two to four hours before bed each night. Doing so allows the corneas to get some full-force oxygen for a few hours. As a nice bonus, removing the lenses after dinner eliminates the problem of accidentally sleeping in them.
In optometry school Dr. Mark Cannon learned of the CLOW issue and tried sleeping in lenses overnight. This was an eye-opening test. The next morning his eyes were so dry and irritated that it was difficult to open the eyes or blink. A drop of artificial tears did help with the discomfort. Even still, this experience made clear the importance of maintaining homeostasis on the ocular surface by avoiding CLOW.
Patients who continue to wear lenses in an extended wear manner may end up with desensitized corneas. The lack of oxygen over long periods can damage the corneal nerves. This means you won’t feel your contacts much, and often the eye is permanently damaged. Re-growing corneal nerves becomes less likely as we age. Having a numb cornea presents a whole other set of health risks called “Neurotrophic Keratitis”.
What Are The Health Risks of Contact Lenses you can sleep with
In addition to Neurotrophic Keratitis, many contact lens abusing patients end up with corneal neovascularization. This is new growth of blood vessels into the cornea (where there should be no blood vessels at all). If this blood vessel growth progresses into the line of sight (central cornea) the vision will be permanently reduced. Corneal edema and superficial keratitis are two other significant risks.
Corneal edema results from hypoxia (lack of oxygen) disrupting the health and function of cells within the cornea that should be pumping water OUT of the cornea. Superficial keratitis is an irritation/ inflammation on the ocular surface that leads to endothelial cell death. This corneal damage is superficial and usually can be healed; ideally with the help of a dry eye specialist like Dr. Mark Cannon. If you develop corneal edema or keratitis it is a warning sign that your contact lens over-wear is causing problems and you should change course.
Another study indicated that corneal ulcers (a bacterial colony growing in the cornea) occur much more frequently in contact lens abusers. Corneal ulcers are typically painful and make your whole eye red and inflamed. Even with early detection and proper medical management, these ulcers can leave behind a permanent scar. Scarring in the cornea is no good and often reduces vision in that eye permanently.
Peer reviewed studies have indicated that patients who sleep in their contacts on a regular basis are 8 times more likely to develop corneal ulcer than patients who wear their contacts responsibly.
We encourage you to have up to date glasses so that you can see with your contacts out. Many of our patients who used to abuse contacts have found relief by switching to single-use lenses. Whatever it takes, let’s keep your eyes healthy. They have to last cradle to the grave.
