Thursday, December 30, 2010

What are the different types of Contact Lenses

People of all ages, from the very young to the elderly, can benefit from wearing contacts to correct vision especially custom contact lenses. They can also be used to treat astigmatism as well as presbyopia.
Contact lenses work on a very simple basis: they stay on the pupil by adhering to the eye’s tear film. There are many wear schedules available, from daily disposables to extended-wear disposables that can last for a week, a month, or even a year.
Besides for aesthetic contact lenses that are used to change the color of the iris, all corrective contact lenses must be fitted and prescribed by an eye care specialist to ensure that they are the perfect fit for the patient’s eyes.
Soft Contact Lenses Are the Most Convenient
Soft contacts are produced from a pliable polymer and water. The water content can vary anywhere between 30% and 40%. This high water content makes soft contacts extremely comfortable to wear since it allows oxygen to reach the cornea. The downfall is that soft contacts are more vulnerable to contaminants because they are so highly permeable. They also have a tendency to dry out eyes since the water also makes the lenses permeable to water, and therefore, draws water away from the eye’s tear film.
Soft toric contact lenses are used to correct for astigmatism in place of traditional spectacles, while bifocal soft contacts are used to treat presbyopia in place of reading glasses.
Hard Contact Lenses Are Almost Obsolete
Hard contacts were the first type of contact lens ever developed. They are the smallest and hardest type of contact lens available. With no permeability to oxygen, the lens must be small to prevent suffocating the cornea. Making the lens small also makes it susceptible to falling out of the eye whenever the wearer blinks. Rigid gas permeable contacts are the better alternative to hard contacts.
Rigid Gas Permeable Contact Lenses Are the Best of Both Worlds
Rigid gas permeable lenses are an innovation that combines the sturdiness of hard contacts with the oxygen permeability of soft contacts. They can last for years if properly used and cared for. For more severe cases of astigmatism, gas permeable contacts may be the only option besides glasses. Initially, these contact lenses may feel a bit uncomfortable, but wearers will adjust rapidly and the lenses will be just as comfortable as soft contacts.
Disposable Lenses Are Maintenance-Free
For people who cannot be bothered by cleaning contact lenses, disposable contact lenses are the way to go. These soft contact lenses are tossed out daily after being worn, thereby eliminating the need for any kind of care or cleaning. The wear schedule for disposable contact lenses varies from daily, to weekly, to monthly replacement requirements, depending on the wearer’s lifestyle. Colored contact lenses are also available as disposable lenses.

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