Extended wear contact lenses give wearers the option of leaving lenses in their eyes for days or even weeks. But just because these lenses are approved by the FDA does not mean they are 100 percent safe for your eyes.
Extended wear contact lenses, like regular contacts, can cause permanent damage to the eyes if not used correctly.
Contact lenses, like glasses, are used to correct vision problems including nearsightedness and farsightedness, and astigmatism. Contact lenses are thin, curved plastic disks that sit inside the eyelid and cling to the layer of tears covering the cornea or front surface of the eye.
Traditional contacts were designed for daily wear and need to be removed, cleaned and stored each night. Extended wear lenses allow wearers to leave the lenses in longer, which means less time is spent cleaning and caring for the lenses.
Disposable lenses are also available that are worn once, whether for one day or longer, and then replaced with a new pair.
A significant health issue with contact lenses is the ability of the lens material to allow oxygen to pass through the lens to reach the cornea.
Many current extended wear soft lenses are made from silicone hydrogel, which is a material that allows more oxygen to pass to the eye and discourages the build-up of proteins and bacteria on the lens. Some lenses of this type are approved for up to 30 days and nights of continuous wear.
Extended wear lenses are also available as rigid gas permeable (GP) lenses.
Some eye care specialists prefer GP lenses because they are smaller and cover less of the cornea than soft lenses. GP lenses also move more with each blink, which may allow better oxygen flow to reach the cornea.
However, the longer any contact lens is worn, the greater the risk that an infection could develop in the eye. Potentially dangerous bacteria and other microorganisms can get caught between the lens and the eye.
When the lens is left in the eye overnight, bacteria can multiply rapidly in the warm, moist environment.