Types of Contact Lenses

Contact lenses can be divided into several classifications:

1. By material characteristics: Soft (cellophane-like) or Rigid (formed flexible plastic).
2. By wear schedule: Daily Wear or Overnight Wear (also called "Extended Wear", amodality which has fallen into disfavor because of the high incidence ofcomplications).
3. By life-span of the lens: Disposable (1 day or 2 week), Planned Replacement (1 month, 3 month or 6 month), or Conventional year or 2 year.
4. By function : Corrective (Spherical, Toric or Astigmatic, or Bifocal), Cosmetic (Color, Crazy Contact Lenses), and Therapeutic.

Sources:
Contact Lens