The first choice when considering contact lenses is which lens material will best satisfy your needs. There are five types of contact lenses, based on type of lens material they are made of:

• Soft lenses are made from gel-like, water-containing plastics called hydrogels. These lenses are very thin and pliable and conform to the front surface of the eye.

• Silicone hydrogel lenses are made of an advanced type of soft contact lens material that allows more oxygen to pass through the lens and reach the front surface of the eye. Silicone hydrogel contact lenses are now the most popular type of contact lenses.

• as permeable lenses. Also called GP or RGP lenses, these are rigid contact lenses that maintain their shape on the eye, enabling them to correct astigmatism and other refractive errors. Gas permeable contact lenses typically are smaller in diameter than soft lenses and are made of highly oxygen-permeable materials. It usually takes some time for your eyes to adjust to GP lenses when you first start wearing them; but after this initial adaptation period, most people find GP lenses are as comfortable as soft lenses.

• Hybrid contact lenses have a rigid gas permeable central zone, surrounded by a "skirt" of hydrogel or silicone hydrogel material. They are designed to provide wearing comfort that rivals soft or silicone hydrogel lenses, combined with the crystal-clear optics of GP lenses.

• MMA lenses are rigid contact lenses that look like GP lenses but are made of a plastic material that is not oxygen permeable. PMMA lenses were commonly prescribed years ago, but essentially have been replaced by gas permeable lenses.