There are two general types of contact lenses: hard and soft. The hardlenses most commonly used today are rigid, gas-permeable lenses(RGP for short). They are made of plastics and other materials such assilicone or fluoropolymers. Hard lenses hold their shape, yet allow the free flow of oxygen through the lenses to the cornea. RGP lenses maybe the best choice when the cornea has enough astigmatism (is shapedlike an egg instead of an orange) that a soft lens will not provide sharpvision for Contact Lance Surgeon Ahmedabad, Contact Lance Surgeon In Ahmedabad. They may also be preferable when a person has allergies ortends to form protein deposits on his or her contacts.
  Soft lenses are the choice of most contact lens wearers. These lensesare comfortable and come in many versions, depending on how youwant to wear them.
  Daily-wear lenses are the least expensive, are removed nightly and arereplaced on an individualized schedule. They should not be used as anextended-wear lens.
  Extended-wear lenses are worn overnight but are removed at leastweekly for thorough cleaning and disinfection. They are beingrecommended less frequently, since there is a greater risk of cornealinfection with any overnight wear of contact lenses.
  Disposable-wear lenses are more expensive, but convenient. They areremoved nightly and replaced on a daily, weekly, biweekly, or monthlybasis. Disposable lenses are sometimes recommended for people withallergies and for those who tend to form deposits on their lenses.
  Coloured contact lenses are contacts that change your eye color, the appearance of your eye, or both. And in the case of circle lenses they can also make your iris appear bigger. Colored lenses are available by prescription and should only be worn after an eye exam and fitting by a qualified eye care professional. Over-the-counter colored contacts, including circle lenses, are illegal and pose a serious danger to your eyehealth. They can cause eye injury, eye infection, and vision loss.
  Toric soft contact lenses can correct astigmatism, but sometimes not as well as RGP lenses do. They usually cost more than other contact lenses.
 Bifocal or multifocal contact lenses are available in both soft andRPG varieties. They can correct near-sightedness, farsightedness andastigmatism in combination with presbyopia. Cleaning and disinfectionare specific to the lens material. Visual quality is often not as good aswith single vision lenses; however, for some people the ability to correctpresbyopia is worth it.
  Uses of Contact lenses
Previously hard contact lenses were used for Keratoconus. Early Keratoconus can be managed by giving rigid contactlenses to the patient which correct the irregularity of thecornea and provide better quality of vision Contact Lance Surgeon Ahmedabad, Contact Lance Surgeon In Ahmedabad. However, the disadvantage of contact lenses is that, in severe cases,optimal fitting is not achieved and rigid lenses are more difficult to wear.