Contact lenses that you can put in and wear continuously for many days are the dream of many contact lens wearers. No fuss about cleaning, storing , inserting or removing them -sounds convenient, doesn't it? But is it safe? Find out if extended wear contacts are right for you.

How do extended wear contact lenses work?

Most contact lenses are daily wear - you wear them during the day and take them out for the night. Lenses have to be taken out because they partially block the flow of oxygen to your cornea. In other words, your eyes need a rest without contacts.

However, many contact lens wearers wish that they didn't have to remove their lenses every evening. Knowing this, contact lens manufacturers have worked really hard to develop a contact lens material that doesn't block oxygen and would allow you to wear your lenses for several days - or even weeks - without risk to your health.

Modern technology allows the production of contact lenses that let through approximately six times more oxygen than ordinary soft contact lenses. Lenses intended for extended wear are made of extra-permeable silicone hydrogel materials and "breathe" so well that oxygen deprivation is no longer a problem, even if you wear your lenses for several days.

Are extended wear contact lenses safe?

Lenses that are FDA approved for extended wear, like Focus Night and Day or Acuvue 2, are safe if you follow your doctor's instructions. They feel quite comfortable for many days, unless you have very sensitive eyes.

The only problem with extended wear contact lenses is that since you don't clean them every day, tiny particles of dust can accumulate on them.

To prevent this keep to the following rules:

• Avoid dusty rooms
• Stay away from cigarette smoke
• Try to keep the water away from your eyes when showering and wear tight goggles while swimming
• Never wear your contact lenses longer than your doctor recommends. Remember weekly disposable extended wear lenses should be thrown away once a week and 30 day wear lenses can only last a month, not a day longer.

Also to minimize the risk of eye infection it is very important to pay attention to how your eyes feel and not to ignore any unpleasant symptoms. If your eyes feel irritated or simply uncomfortable, take the lens out immediately and give your eye 6-8 hours rest. Rinse the lens well before putting it back in. And if discomfort continues, don't ignore it, see your doctor. Maybe extended wear lenses are not for you after all.

Which extended wear contacts are available on the market?

Two brands of extended wear contact lenses are FDA approved for 30 day continuous wear - Focus Night and Day by Ciba Vision and PureVision by Bausch & Lomb. Other lenses can be worn for a week without removal. The most popular of these is Acuvue by Johnson and Johnson

Are extended wear contact lenses more expensive than the regular contacts?

Surprisingly, the price difference isn't that big. Extended wear contact lenses are slightly more expensive that the usual weekly or monthly disposable contacts, and they are cheaper than daily disposables. Also, since you will wear your contacts for a week or a month and then discard them, you save on cleaning and storing solution. So cost is not an issue when it comes to extended wear contacts.

If the idea of wearing contact lenses continuously for several days appeals to you, ask your doctor if extended wear contacts will work for you.