There are two general categories of contact lenses - soft and rigid gas permeable (RGP).

Soft Contact Lenses
Soft contact lenses are made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft contact lenses may be easier to adapt and adjust and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide even more oxygen to your eyes while you wear your lenses.

Rigid Gas Permeable (RGP) Contact Lenses
Rigid gas permeable contact lenses (RGPs) are more durable and resistant to deposit buildup, and generally give a clearer, crisper vision. However, they are not as comfortable as soft contacts and it may take few weeks to get used to wearing RGPs. They tend to be less expensive over the life of the lens since they last longer than soft contact lenses. They are easier to handle and less likely to tear.

Advantages and Disadvantages of Various Types of Contact Lenses

Rigid gas-permeable (RGP)

Daily-wear soft lenses 
Extended-wear

Extended-wear disposable

Planned replacement