Soft contact lenses are thin, dome shaped discs made of complex plastic material positioned on the cornea to focus images on the retina. Contact lenses are a safe, convenient, comfortable and affordable alternative to spectacles. There are basically two types of lenses, rigid gas permeable lenses (RGP) and soft lenses.
RGP lenses are semi- rigid lenses made from a plastic that allows oxygen through the eye and are the best, clinically. They are also easy to take care of, durable and give a clear vision. They are useful to all types of vision correction like astigmation, bifocals, and post surgery and cosmetic for all groups of age.
Soft lenses: Soft lenses made from water absorbing plastics, are flexible and membrane like for maximum comfort. Since they do not displace easily from the eyes, they are ideal for sports.
Silicon based soft lenses allow maximum oxygen to the cornea and therefore they can be safely worn for a month continuously. Soft lenses can correct all types of refractive errors. They are available for Toric (to correct astigmation), bifocal, weekly disposable, extended wear and cosmetic purposes.
Toric lenses: Toric lenses are made from the same material as regular contact lenses, the difference being in the design of the lenses. Toric lenses have two powers of curvatures at different angles, one for astigmation and the other for myopia or hyperopia. Toric contact lenses have a mechanism to keep the lens stable on the eyes even while blinking. The cost of the Toric lenses is more than the spherical lenses and fitting expenses are also more.
Disposable lenses are replaced every two weeks or sooner and are designed to be worn and then replaced with a new pair of lenses. Disposable contact lenses are favored because of their health and convenience benefits.
Daily disposables or one-day disposables are contact lenses that are discarded every night and replaced in the morning with a new pair. This option is the best because there is no lens cleaning and since there are no lens deposit build up there are no eye problems.
Extended wear lenses are approved to be worn without removal up to seven days .A “super permeable” lens material
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