What Are Contact Lenses Made Of?

Contact lenses are made of plastic. To be more specific, contact lenses are made of polymers, or plastics that are thin, clear and curved. Contact lenses first began to become available commercially in the 1960's. In those days, the common material used to make contact lenses was polymethyl methacrylate (PMMA). PMMA is used to make latex paints, Plexiglas and Lucite, and also found in such places as aquariums and ice hockey rinks, where they are used to make the barriers. PMMA contact lenses were discontinued as they were unpopular and uncomfortable for the wearer and they were hard and rigid and did not allow the free circulation of air to the cornea, which could be harmful for the eyes.

Soft contact lenses made of a polymer called nitrogen-containing polycrylamide were introduced in the United States in 1971. This polymer dissolves in water and is similar to the polymers used to make acrylic fibres, which are in turn used to make fabrics. Since between 38 to 79 per cent of a soft contact lens is made up of water, it is made up of crosslinked polycrylamide, which absorbs water and hence is a good material for making soft contact lenses. Soft contact lenses are still popular among wearers all over the world.

Rigid gas-permeable lenses, also known by their abbreviation RGP's, were introduced in the market in 1979. RGP lenses combined PMMA with silicone and fluoropolymers. This enables oxygen to pass directly through the lens to the eyes, and is comfortable for the wearer. RGP's, as the name suggests, are rigid, so the person's vision is crisper. RGP's are a better solution to correct defects such as astigmatism and bifocal needs.

To be more specific with the type of plastic.Group 1 Contact Lenses (Low water content, non-ionic)

• Tefilcon (38% water) – Cibasoft, Illusions, Torisoft
• Tetrafilcon A (43% water) – CooperToric, Preference, Preference Toric, Vantage
• Crofilcon (38% water) – CSI, CSI Toric
• Ploymacon (38% water) – Biomedics 38, Edge III, Z4/Z6, Soflens 38
• Lotrafilcon A (24%) – Focus Night & Day
• Lotrafilcon B (38%) – O2Optix
• Galyfilcon A (47%) – Acuvue Advance with Hydraclear, Advance for Astigmatism
• Senofilcon A (38%) – Acuvue Oasys

Group 2 Contact Lenses (High water content, non-ionic)

• Alfafilcon A (66%) – Soflens 66
• Omafilcon A (62%) – Proclear Compatibles
• Nelfilcon A (69%) – Focus Dailies, Dailies Toric
• Hilafilcon A (70%) – Soflens 1-day
• Hilafilcon B (59%) – Soflens 59

Group 3 Contact Lenses (Low Water content, ionic)

• Phemfilcon A (38%) – Durasoft 2
• Balafilcon A (36%) – Purevision

Group 4 Contact Lenses (High Water, Ionic)

• Etafilcon A (58%) – Acuvue, Acuvue Bifocal, Acuvue 2, Acuvue 1-day
• Ocufilcon D (55%) – Biomedics 55, Biomedics 55 Premier
• Phemfilcon A (55%) – Durasoft 3, Freshlook, Wildeyes
• Methafilcon A (55%) – Sunsoft Eclipse, Revolution, Sunsoft Toric
• Vilfilcon A (55%) – Focus 1-2 Week, Focus Toric, Focus Progressives

Crap

Most contact lenses are mass produced.    * Spin-cast lenses - A spin cast lens is a soft contact lens manufactured by whirling liquid silicone in a revolving mold at high speed.[32]    * Lathe turned - A lathe turned contact lens is cut and polished on a CNC lathe.[32] The lens starts out as a cylindrical disk held in the jaws of the lathe. The lathe is equipped with an industrial grade diamond as the cutting tool. The CNC Lathe turns at nearly 6000 RPM (revolutions per minute) as the cutter removes the desired amount of material from the inside of the lens. The concave (inner) surface of the lens is then polished with some fine abrasive paste, oil, and a small polyester cottonball turned at high speeds. In order to hold the delicate lens in reverse manner, wax is used as an adhesive. The convex (outer) surface of the lens is thus cut and polished by the same process.    * Molded - Moulding is used to manufacture some brands of soft contact lenses. Rotating moulds are used and the molten material is added and shaped by centrifugal forces. Injection moulding and computer control are also used to create nearly perfect lenses.[33].    * HybridsHydrogel materials
Asmofilcon ABalafilcon AComfilcon AEnfilcon AGalyfilcon AHilafilcon AHilafilcon BHioxifilconLotrafilcon BMethafilcon AOmafilcon APhemfilcon APolymaconSenofilconTetrafilcon AVifilcon A

It's made up of plastic...

Plastic

Contact lenses are made of thin layers of curved plastics known as polymers. These transparent, soft and flexible polymers were invented in 1960. These lenses restrict oxygen to pass to the cornea which is often considered as detrimental. Previously hard lenses were prevalent but now after the invention of soft contact lenses in 1971, it has been commercialised. Crosslinked polyacrylamide is well suited for making contact lenses as they absorb water.

Almost 38% to 79% of the contact lens has the ability to be flexible if kept in water.

In 1979, the rigid gas permeable lenses were out in the market which was made out of silicone and fluoropolymers.

In 1987, the disposable contact lenses with different colors hit the market and the disposable lenses with ultra violet absorbers were invented in 1996.