What are contacts made of? This is an important question for your eye physician to discuss. Most vision patients are surprised to discover how much more comfortable and convenient contact lenses have become in the past decade.
Today’s contact lenses are made up of three main materials. These modern contact lens materials are synthetic and fashioned from products that allow greater amounts of oxygen to reach the cornea. Lack of oxygen to the eye can degrade patients’ vision health, so advances in oxygen transmissability has allowed users to wear their contact lenses with comfort and convenience for longer periods of time than a decade ago.
Each type of contact lens offers different advantages to patients. Depending on your eye prescription and your lifestyle, you and your doctor can discuss what type of contact lens will best suit your needs. Before having that discussion with your doctor, it may be helpful to understand what some of the basic advantages that each contact lens material provides. Soft contact lenses, rigid gas permeable (RGP) contacts and hybrid contact lenses all offer different benefits to patients.
Soft Contact Lens Materials
Soft contact lenses have revolutionized the contact industry. This particular kind are made of a flexible and water-absorbing material known as hydrogel. They are comfortable, flexible and one of the most popular types of contact lenses on the market because patients can wear them immediately without going through an acclimation period.
In essence, a soft contact lens is made from a technology that soaks up water to keep the cornea hydrated and supple. There is quite a bit of variation with hydrogels. The amount of water content they soak up can vary from 38 to 75 percent based on the weight of the contact lens. While a higher water content will improve the degree of oxygen that transmits to the cornea, it also thickens the contact lens. Those patients that like a thinner-feeling contact lens, might choose the option for a lower water percentage of their soft contact lens.
Since hydrogels are made of a large amount of water but are also plastic, a drawback can be that they are either ionic or non-ionic. Remember back to science class when you did all that water testing in chemistry class? Ionic materials are attracted to negatively charged surfaces. This means tears, which contain natural protein deposits, can adhere to soft contact lenses that are ionic. Because of this, non-ionic soft contacts have been developed. Ask your eye physician if non-iconic lenses are a better choice for you.
Silicone Hydrogel Soft Contacts
A hybrid of soft contact lenses that has become very popular is known as a silicone hydrogels. Some scientific studies suggest that silicone hydrogels may transmit six times more oxygen to the cornea than other soft contact lens materials. This technological advancement has made it possible for the contact lens industry to create extended-wear and daily disposable contact lenses – like Dailies Aquacomfort Plus and 1 Day Acuvue Moist – that provide all-day comfort using a silicone hydrogel material.
Rigid Gas Permeable (RGP) Contact Lens Materials
Gas permeable contact lenses are made from a plastic silicone that conducts oxygen. Many consumers confuse these contact lenses with the old-fashioned hard contact lenses. Actually, the old hard contact lenses have become obsolete. The new ridged contact lenses were introduced in the late 1970s and are also made from a type of silicone that provides them some flexibility. The new product is more comfortable and transmits oxygen to the cornea to provide better eye health. As a matter of fact, gas permeable contact lenses transmit more oxygen to the corena than soft contact lenses. Another advantage is that gas permeable lenses do not attract protein deposits, which can cause cloudy contact lenses, so they last longer than traditional soft contact lenses.
- While a soft contact lens is a comfortable fit for a patient right from the get go, patients who wear a gas permeable lens must go through an acclimation period to adjust to wearing them.
- Gas permeable contact lenses are created from a firm plastic material that retains its shape when a patient blinks. This advantage provides a sharper form of vision.
- Gas permeable contact lenses are durable. Although they are breakable if you step on them, they do not tear as easily as soft lenses.
- Gas permeable contact lenses do not contain water, so protein deposits from tears do not stick to the lenses as readily as they do to soft contact lenses.
- Gas permeable contact lenses can last for years with proper care.
Hybrid Contact Lens Materials
If comfort is everything to you, the new hybrid gas permeable contact lenses may be the best choice as they provide the clarity of an RGP lens and the comfort of soft contact lenses.
Hybrid contact lenses were created to offer a central optical zone, the materials of which are created from a gas permeable lens substance, and then surrounded by a silicone hydrogel lens material. In essence, this hybrid combined the two exisiting technologies on the market into one unique type of contact lens.
Hybrid contact lenses are manufactured by Synergies in the United States. The company sells a wide range of contact lenses under the brand names known as Ultra Health, Duette and SynergEyes. These products work well for patients who require vision correction for multifocal hybrid lenses, or presbyopia.