One of the biggest advancements in contact lens technology has been the development of the extended wear lens. Extended wear contact lenses can be left in place around the clock for seven days (and longer depending on the type of material used) before needing to be removed. Prior to that, only daily wear contact lenses were available.
The key difference between daily wear and extended wear contact lenses is the flow of oxygen. Extended wear lenses can transfer oxygen from the air through the contact lenses and onto the cornea so that it can breathe. When the cornea doesn’t get an adequate supply of oxygen, it is susceptible to a number of different eye problems including giant papillary conjunctivitis and corneal edema.
Extended Wear Contact Lenses
Extended wear contact lenses are perfect for busy people because they require minimal maintenance. They’re also a good choice for individuals who work odd hours and double shifts such as doctors and firefighters. Extended wear disposable lenses are the most convenient because they’re simply thrown away after they’re removed.
The first extended wear lenses were not designed to be thrown away. Wearers reinserted the same pair after removing them for routine cleaning and disinfecting. Because it was not possible to completely cleanse and disinfect these lenses, infections and irritations were common. Infections, although more rare, are still a risk and those who choose extended wear lenses are advised to get frequent eye examinations.
Even though they’re convenient, these lenses are not right for everyone. Some are uncomfortable with the idea of leaving their contacts in while sleeping. They think (incorrectly) that they might become lost inside the eye and such thoughts can cause anxiety. For others, the eyes just aren’t able to get enough oxygen, and they need to switch to daily lenses.
Daily Wear Contact Lenses
Daily wear soft lenses have always been the most popular of the contact lens types. They’re soft and comfortable, cause minimal eye problems and they’re easy to get used to. Because they are made mostly of water, they adhere well and float freely on the surface of the eyes.
They’re perfect for those involved in sports and hobbies where wearing eyeglasses can become a safety issue. They’re made from a more durable plastic than disposable daily wear lenses so they’re not as likely to tear from handling. And since these lenses don’t need to be replaced until they either become damaged or the wearer’s prescription changes, they can be the most cost effective of the various types of lenses.
The downside of daily wear soft contact lenses is that they do require routine maintenance. They need to be thoroughly cleaned and rinsed before they’re stored otherwise protein will begin building up. Although daily cleaning takes only minutes, it’s an easy step to skip because to the naked eye, the contacts don’t appear ‘dirty’. Disposable daily wear lenses are practically maintenance-free and are a better choice if the wearer is not disciplined enough to follow a regular contact lens cleaning schedule. They’re still removed daily, but they’re disposed after a few weeks.