Contact lenses are medical devices placed directly on the eye to correct vision, offering an alternative to eyeglasses. Among the various types available, “conventional” contact lenses refer to those designed for a longer replacement schedule, distinguishing them from more frequently replaced options. These lenses provide clear vision for many common refractive errors.
Characteristics of Conventional Lenses
Conventional contact lenses are soft lenses made from hydrogel materials, which are flexible plastics that absorb water and allow oxygen to reach the cornea. Their defining feature is a prolonged replacement schedule, often quarterly or annually, though some can be replaced monthly or every two weeks.
These lenses are designed for daily wear, meaning they are inserted in the morning and removed at night before sleep. This extended lifespan means they require a consistent daily cleaning and disinfection routine to maintain eye health and clarity of vision. Conventional lenses are widely used to correct various vision impairments, including nearsightedness, farsightedness, and astigmatism.
How Conventional Lenses Differ
Conventional lenses stand apart from other popular contact lens types primarily in their replacement frequency and care requirements. Daily disposable lenses, for instance, are worn once and then discarded, eliminating the need for cleaning and storage solutions. This single-use design also reduces the risk of deposit buildup and infections associated with reuse.
Extended wear lenses, conversely, are designed to be worn overnight for several days or even up to 30 days continuously, though many eye care professionals recommend daily removal and cleaning for these as well. Unlike soft conventional lenses, Rigid Gas Permeable (RGP) lenses are made from firm, durable plastic that maintains its shape. RGP lenses provide sharper vision and are more resistant to deposits but require an adaptation period.
Managing and Caring for Conventional Lenses
Proper management and care of conventional contact lenses are important for preventing eye infections and ensuring comfortable wear. Each time lenses are removed, they require a thorough cleaning process. This involves placing a lens in the palm of a clean hand, adding a few drops of multipurpose solution, and gently rubbing the lens with a fingertip for about 20 seconds.
After cleaning, the lens should be rinsed with fresh solution before being placed into a clean lens case. The case must then be completely filled with fresh disinfecting solution, ensuring the lens is fully submerged. It is important to never “top off” old solution with new, as this reduces the effectiveness of disinfection and can promote germ growth. Lens cases should be rinsed with fresh solution after each use, allowed to air-dry upside down with the caps off, and replaced every one to three months to maintain hygiene.