Contact lenses offer a popular alternative for vision correction, providing convenience and an unobstructed field of view. However, these small medical devices require careful handling and adherence to specific wear schedules to maintain eye health. Understanding how long contact lenses can safely remain in the eyes is essential for avoiding potential complications and preserving clear vision.
Understanding Contact Lens Types and Wear Schedules
Contact lenses are categorized by their recommended replacement frequency, which dictates how long they can be worn. Daily disposable lenses are designed for single-day use and are discarded before sleep. This provides a fresh, sterile lens each day, minimizing deposit buildup and reducing the risk of contamination.
Two-week and monthly disposable lenses are worn daily but must be removed each night for cleaning and disinfection. These lenses are then replaced with a new pair every two weeks or every month. Extended wear (EW) lenses permit continuous wear, including overnight, for a specified period, typically up to six nights and seven days. Some extended wear lenses are approved for up to 30 days of continuous use under professional supervision. These lenses are often made from silicone hydrogel, a material that allows more oxygen to reach the eye compared to conventional hydrogel lenses.
Risks of Over-Wearing Contact Lenses
Exceeding the recommended wear time for contact lenses can lead to several adverse effects on eye health. One significant concern is corneal hypoxia, where the cornea, the clear outer layer of the eye, receives insufficient oxygen. Prolonged oxygen deprivation can cause the cornea to swell and become opaque, potentially leading to the growth of new blood vessels into the cornea, known as corneal neovascularization. These vessels can obstruct vision and indicate long-term damage.
Over-wearing also increases the risk of infections, such as keratitis, an inflammation of the cornea. Bacteria, fungi, or amoebas can proliferate on the lens surface or within small abrasions on the eye. Untreated keratitis can result in corneal ulcers, which are open sores, and potentially lead to permanent vision loss. The natural tear film can also be disrupted, leading to dry eye symptoms like dryness, itching, and burning.
Another issue is giant papillary conjunctivitis (GPC), an allergic reaction characterized by small bumps on the inner surface of the eyelids. This condition can cause discomfort, itching, and increased mucus production, making contact lens wear challenging. Over-wearing can also lead to corneal abrasions, which are scratches or injuries to the eye’s surface.
Recognizing Symptoms of Eye Issues
Recognizing signs of eye irritation or infection is important for contact lens wearers. Common symptoms include unusual redness of the eye, discomfort, or a gritty sensation. You might also experience pain in the eye, excessive tearing, or an unusual discharge.
Other indicators can include blurred vision or increased sensitivity to light. Swelling around the eye or white or grayish spots on the cornea also warrant attention. If any of these symptoms occur, it is important to remove your contact lenses immediately and do not reinsert them. Prompt consultation with an eye care professional is necessary to determine the cause and receive appropriate treatment, helping to prevent serious complications.
Best Practices for Contact Lens Hygiene
Maintaining good hygiene is essential for safe contact lens wear. Always wash hands thoroughly with soap and water and dry them with a clean, lint-free cloth before handling lenses. This prevents the transfer of microorganisms to the eye.
For reusable lenses, always use fresh, sterile contact lens solution for cleaning and storage. Never use tap water, saliva, or homemade saline solutions, as these can introduce harmful pathogens. Even with “no-rub” solutions, rubbing and rinsing the lenses with clean fingers is recommended to effectively remove debris and deposits. The lens case should be cleaned with fresh solution after each use, allowed to air dry, and replaced at least every three months to prevent bacterial buildup. Avoid “topping off” old solution with new, as this dilutes the disinfectant and can lead to contamination.