A clear lens that focuses light, such as in a camera or microscope. Contact lenses can correct refractive errors to make your vision clearer and are safe when prescribed by an eye care provider and worn according to a prescribed schedule.

Lenses can be soft or hard, and come in a variety of colors to brighten your irises. But they all serve the same purpose: to bend light so it focuses on the retina.

Soft Contacts

Historically, contact lenses were made with blown glass. Today’s soft contacts are much more comfortable, though the term “hard” is still often used for original PMMA (polymethyl methacrylate) lenses and RGPs.

Unlike hard lenses, which are placed directly on the cornea, soft contact lenses are typically inserted on top of the sclera of the eye and then slid into place. Your eye care professional can recommend specific lens types, prescriptions and designs to suit your lifestyle and preferences.

There are many different contact lens materials available, and it is important that you understand what the US Adopted Name of each lens material means, as this helps in identifying the type of material and the manufacturer. For example, etafilcon A and lotrafilcon A are both the same contact lens material; only the US Adopted Name distinguishes them. Each type of contact lens is also manufactured in a slightly different way. Using rotary molding and injection molding, the different types of soft contact lenses are formed by centripetal forces into near perfect shapes.

Rigid Gas-Permeable Contacts

The eye doctors at EyeDoctors can help you determine if gas permeable (GP) contact lenses are the right choice for your vision correction needs. GP contacts provide sharper, clearer and more comfortable vision than traditional soft contact lenses, plus they’re long lasting and less expensive over time.

Rigid GP lenses are made from durable plastics that allow oxygen to pass through the lens and reach the cornea. These types of contacts may be appropriate for some patients with a more irregularly shaped cornea due to scarring, surgery or trauma. They are also a good fit for those who have allergies or other concerns about wearing soft contact lenses.

Always follow the advice from your eye doctor about the best cleaning, storing and care of your GP lenses. Use the solution that is suggested by your eye doctor for your particular brand of GP contact lenses, and avoid touching the lens or case to anything other than clean hands.

Astigmatism Contacts

The eye doctors at The EyeDoctors can prescribe contact lenses that help with astigmatism. They can include soft toric lenses or rigid gas-permeable toric contacts, and these are designed differently than standard contact lens to focus light correctly. These lenses feature power meridians in different directions on the lens to compensate for astigmatism.

These lenses also have a soft “skirt” around the lens to keep it from moving or shifting after you blink or move your gaze. And they feature a higher water content or oxygen permeability than traditional lenses, so the cornea gets more moisture and the eyes are less likely to develop dryness or other discomforts from wearing them.

Some minor cases of astigmatism may not need treatment, but moderate to severe cases can be corrected with contact lenses, glasses, or surgery. Rigid contact lenses are usually prescribed to correct astigmatism, but soft toric contacts can also help. And a type of eye surgery called orthokeratology (ortho-k) can temporarily correct astigmatism for some people by reshaping the cornea.

Multifocal Contacts

Many people develop a condition called presbyopia as they age, which makes it difficult to see nearby objects. This condition can be corrected by wearing contact lenses with a multifocal lens design that allows you to simultaneously view distance and near objects.

Multifocal contact lenses contain multiple optical zones with different refractive powers, which enable you to see at various viewing distances. They are available as either bifocal or progressive (varifocal) lenses.

Power maps, centered on the pupil, and through-focus visual strehl for a variety of soft multifocal contact lenses including Acuvue Oasys, Dual Focus, Purevision Multifocal, and Airoptix (left to right). The differences between these lenses are most apparent in the zone design and the transition between near and distant vision, as shown by the dotted lines in the center of the graph. Through-focus performance varies significantly with lens design, ocular aberrations, and visual adaptation.