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Contact Lenses Facts


 

One-day disposable blue color contact lensA contact lens (also known simply as a "contact") is a corrective, cosmetic, or therapeutic lens usually placed on the cornea of the eye. Modern contact lenses were invented by the Czech chemist Otto Wichterle, who also invented the first gel used for their production.

Contact lenses usually serve the same corrective purpose as conventional glasses, but are lightweight and virtually invisible — many commercial lenses are tinted a faint blue to make them more visible when immersed in cleaning and storage solutions. Some cosmetic lenses are deliberately colored for altering the appearance of the eye.

It has been estimated that about 125 million people use contact lenses worldwide (2%), including 28 to 38 million in the United States and 13 million in Japan. The types of lenses used and prescribed vary markedly between countries, with rigid lenses accounting for over 20% of currently-prescribed lenses in Japan, Netherlands and Germany but less than 5% in Scandinavia.

People choose to wear contact lenses for various reasons. Many consider their appearance to be more attractive with contact lenses than with glasses. Contact lenses are less affected by wet weather, do not steam up, and provide a wider field of vision. They are more suitable for a number of sporting activities. Additionally, ophthalmological conditions such as keratoconus and aniseikonia may not be accurately corrected with glasses.

Manufacturing of Contact Lenses

Most contact lenses are mass produced.

Spin-cast lenses - A spin cast lens is a soft contact lens manufactured by whirling liquid plastic in a revolving mold at high speed.

Lathe cut - A lathe cut contact lens is cut and ground on a lathe.

Molded

Hybrids

Although many companies make contact lenses, there are four major manufacturers: Vistakon/Johnson & Johnson, CIBA Vision, Bausch & Lomb, and CooperVision.