The longer a contact lens is worn, the less oxygen the eye receives. The cornea needs to receive oxygen directly from the air, and contact lenses inhibit this process to some extent. If your eyes don't get enough oxygen, you can have symptoms including eye pain, blurred vision, red eyes, light sensitivity, tearing and irritated eyes. If you experience any of these symptoms from contact lens over-wear, make sure to see your eye doctor. You may need to be treated for any damage to your eye, and you may need to take a break from wearing your lenses.

Generally, we do not recommend sleeping in contact lenses on a regular or prolonged basis. The eye is a dark, warm place while you are sleeping. Bacteria thrive in dark, warm places. There are contact lenses FDA approved to sleep in, but they should always be removed and thoroughly disinfected every week.

The majority of contact lens wearers wear soft contacts: almost 95%. However, the safest, easiest to handle, best for preventing the deterioration of vision, best value, and often the most comfortable (when designed correctly) contacts are rigid gas permeable contact lenses (RGP). So why are they not as popular as soft lenses? These are custom lenses and the quality of the design depends on the skills of the eye doctor; they're much more complicated to fit than the one-size-fits-all soft contact. They can be designed for any prescription, for any amount of astigmatism, with bifocal or multifocal prescriptions, or for corneal molding which are only worn while you sleep. The RGP lens allows over fifty times more oxygen through to the eye than a typical soft lens, reducing the risk of irritation and infection. These lenses are also much more durable than soft contact lenses, typically lasting for years, which can save money in the long run.