Extended Wear Contact Lenses

By Nancy Del Pizzo and Liz Segre,
with updates and review by Gary Heiting, OD

Extended wear contact lenses may be the right option for you if you would like to wake up each day with clear vision.

Contact lenses are available for two different wear schedules:

• daily wear (you remove them before sleeping)
• extended wear (you leave them in overnight)

In the United States, the FDA has approved some contact lenses for daily wear only and others for extended wear. Extended wear lenses allow more oxygen to reach your cornea.

Most extended wear lenses are FDA-approved to be worn without removal for up to seven days. A newer type of soft contact lens material, silicone hydrogel, is considered "super-permeable," and some lenses made from this material are approved for up to 30 days of wear without removal.

Also, some gas permeable lenses can be worn for up to a month at a time. This 30-day type of extended wear lens sometimes is called "continuous wear."

After recent improvements in design and materials, these lenses now can be worn safely for the full 30 days for those who can tolerate them. Even if you don't feel comfortable wearing the lenses for the full time period, you still can change them out at extended wear intervals that best suit you.

Problems With Earlier Versions of Extended Wear Contacts

For a brief time period, extended wear contact lenses were out of favor with eye care practitioners because of the increased risk of eye infections associated with overnight wear.

The FDA first approved certain contact lenses for overnight wear in 1981. These lenses were approved for up to two weeks of wear without removal. Shortly thereafter, some lenses were approved for up to 30 days of continuous wear.

Researchers found, however, that the incidence of eye infections was greater among people who slept while wearing contact lenses. In response, the FDA changed the maximum extended wear period to seven days.

However, many eye care practitioners decided that any overnight wear was too risky, and they began encouraging patients to always remove their contacts before sleep, even if the lenses were FDA-approved for extended wear.

Extended wear lenses are a concern because potentially dangerous organisms, which might enter your eye from your fingers or other means, could become lodged under your lenses.

These organisms thrive in the warm, moist environment under your contact lenses. And because contact lenses reduce the oxygen supply to your cornea, your eye is less able to fight off infection from bacteria, fungi and other organisms.

Contact lens-related infections can range from an annoying case of pink eye to more serious conditions — even some that can lead to blindness. When contact lenses remain in your eyes continuously for several days, the risk of these problems increases.

With extended wear contact lenses, you can wake up in the morning with clear vision.

A Comeback for Extended Wear

Today, overnight contact lens wear is no longer taboo. So what changed?

The following advances in contact lens technology made extended wear contact lenses significantly safer:

• The introduction of disposable contact lenses reduced some health concerns about extended wear lenses. Previously, extended wear lenses were removed weekly, but they were re-used week after week, for months. Although the lenses were cleaned with some type of contact lens solution, it was impossible to remove all the proteins, lipids and other deposits that collected on the lens. These deposits formed a potential breeding ground for infection-causing organisms and caused inflammation and discomfort.
• Today, extended wear lenses are typically disposable contacts. If you sleep in your lenses, not only do you remove them at least once a week, but you discard them periodically and start with a fresh pair. This avoids long-term deposit buildup and helps maintain eye health.
• A new generation of contact lenses — silicone hydrogel lenses — provide much more oxygen to the eye than conventional soft lenses. Not only do these materials make overnight wear safer than before, they deliver so much oxygen to the cornea that some brands of silicone hydrogel lenses are approved for 30 days of continuous wear.
• Many wearers have adopted "flexible wear." This means using extended wear contact lenses but typically removing them each night. However, when you want to sleep in them — during a weekend camping trip, for example, or even an afternoon nap — you can do so safely.

Minimize Extended Wear Risk

Despite these improvements, wearing contact lenses during sleep still carries a greater risk of complications than removing your lenses daily.

If you wear extended wear lenses, you can reduce your risk of infection by following your doctor's instructions for lens replacement and care.

Studies show many infections and other complications are related to improper cleaning and disinfecting. You can bypass the need for daily lens care with overnight wear, but it's critical to discard your lenses as instructed by your eye doctor.

Usually this means replacing your lenses weekly, every two weeks or monthly, depending on the type of lenses you have.

Keep in mind that exposure to smoke, wearing your contacts when swimming and previous eye irritations or infections are additional risk factors for extended wear contact lens complications.

Another way to avoid a problem with extended wear lenses is to "listen" to your eyes and take action, if necessary. Every day, take a good look at your eyes in a mirror. They should always:

• Look good
• Feel good
• See well

If you experience red or irritated eyes or reduced vision that does not improve with fresh lenses or lens cleaning, remove your lenses and consult your eye doctor immediately.

Joseph T. Barr, OD, also contributed to this article.

[Page updated December 2008]