Eye Care > Common Terms > Contact Lenses

Contact lenses

When choosing contact lenses, there are more things to consider than just “daily” or “extended wear.” Some terms you may want to discuss with your Park Nicollet Eye Care professional are defined here.

Bifocal lenses

Bifocal contact lenses are designed for people with a condition called presbyopia. Bifocal lenses are available in both rigid gas permeable (RGP) lenses and soft lenses.

Replacement schedule

Refers to how long a wearer can safely use a contact lens before needing to throw it away. Rigid gas permeable (RGP) lenses are generally replaced every couple years, while soft lenses have numerous replacement schedules.

Rigid gas permeable lenses

One of the two main types of contact lenses. Soft lenses is the other. Rigid lenses can take longer for wearers to adapt to, but they are more durable and more resistant to deposit build-up. They also are used for certain corrections, such as astigmatism.

Soft lenses

One of two main types of contact lenses. Rigid gas permeable lenses is the other. Soft lenses can contain anywhere from 25 percent to nearly 80 percent water. First-time users to usually adapt to these very easily.

Toric lenses

Toric lenses are designed for those people diagnosed with astigmatism. These lenses are available in either rigid gas permeable (RGP) or soft lenses. Toric lenses have two powers, created with curvatures at different angles. They also are designed to keep the contact lens as stable as possible on the eye, limiting movement when you blink. To provide clearer vision, toric contact lenses are not able to rotate on your eye.

Wear schedule

A wear schedule refers to whether or not a wearer can sleep while wearing their contacts. The kind of lenses you can sleep in are called “extended wear,” while lenses that must be removed are called daily wear.