••●||► Types of contact lenses

There are several types of contact lenses. Soft lenses and rigid lenses are the two types of lenses the most common.

Soft lenses

Soft lenses are the most common, as very adaptable, affordable, and easy to use for most people. Indeed, there are soft contact lenses daily, weekly, biweekly, monthly and yearly. Also, most cosmetic and therapeutic contact lenses are soft lenses.

Hard lenses

There are two kinds of rigid lenses (which replaced the old hard lenses): the first hard lenses are longstanding PMMA (or Perspex / Plexiglas) and modern hard lenses is referred to as RGP (Rigid Gas Permeable ).

Rigid lenses are a modern type of lens that meets the particular carrier likely to suffer from dry eye, due to their high oxygen permeability. They are less common than soft lenses.

Most of the hard lenses are more expensive than soft lenses, but the frequency of replacement is generally less regular. Indeed, some hard lenses can be used for one to two years.

There are significant differences in the requirements of rigid lenses in different countries: they represent 20% of prescriptions in Japan, the Netherlands and Germany but only 5% of prescriptions in Scandinavia.

••●||► The History Of Contact Lenses

A contact lens (also known as contact lens, lens or contact) is a corrective lens, cosmetic or therapeutic placed on the cornea of the eye.

Leonardo da Vinci in 1508, was the first to have had the idea of ​​contact lenses, they will be developed in 1887 by the German ophthalmologist Adolph Eugene Fick.

The soft contact lenses were invented in 1961 by the Czech chemist Otto Wichterle, who also invented the first hydrogel used in their production. They have the same function as eyeglasses but are distinguished by their small size and near-invisibility. Many contact lenses are slightly tinted blue to better distinguish them in their storage case. Cosmetic contact lenses are specifically colored to alter the appearance of the eye.

About 125 million people worldwide wear contact lenses (2%) that 28-38000000 United States, and 13 million in Japan. The types of lenses used and prescribed vary markedly between countries, with rigid lenses that count approximately 20% of prescribed lenses in Japan, the Netherlands and Germany and less than 5% in Scandinavia.

Users choose to wear contact lenses for Various Reasons. Many Consider Themselves more attractive by wearing contact lenses of glasses INSTEAD of view. Contact lenses are not Affected by the weather, do not and do not affect s'embrument vision. They Are Widely Used by athletes particularly. Finally, Eye Problems Such as keratoconus or better aniseiconia are Treated by wearing contact lenses.