Although contact lenses for more than 100 years, contacts have modern plastic instead of glass, were introduced in 1948. They are worn directly on the cornea of the eye and if it is properly installed, can bring in almost natural views.
The first plastic lenses were made of hard plastic than PMMA (polymethylmethacrylate) and do not deliver oxygen to the cornea. In the year 1971 were imported soft contacts. Soft lenses are made from aBind water loving "or hydrophilic polymer that can be quickly up to 74 percent water. Soft contacts replaced hard lenses in popularity as they are usually more comfortable for the wearer.
The silicone hydrogel lenses entered the market in 1999, and is the world's fastest growing contact lens segment. The material is resistant to drying out and allows a high oxygen transfer to the eyes. Contact lenses are a medical device, and as such, theymust be prescribed and properly fitted by an eye care doctor. You are on the basis of the material they are made to bear the length of that group the frequency of disposal and lens design.
Until the introduction of extended wear contact lenses in the year 1979, all the necessary contacts will be expanded and cleaned nightly. Today, the members of an extended wear lens to the eye that are worn overnight to seven days without requiring removal of a continuous wear lens, which can be wornas long as 30 days without removal, and a daily wear lens, which must be removed every night.
The major disadvantage of contact lenses is that proteins and lipids, which are naturally found in tears at their surface, making it vulnerable to natural disasters deposits such as calcium. Eye discomfort and dryness can be made up of assets to create a water-rejecting film on the front of the lens. The deposits can also be a source of food forInfection-causing bacteria. This makes it particularly important to the advice of a practitioner's Eye Care of care and replacement follow. The primary function of a contact lens is a vision problem, it has been prescribed to correct address. Eye care professionals need to work on a lens that actually fits the patient's eye to be found, may, taking into account the patient's other eye diseases, such as dry eyes.
Contact lenses come in different shapes --spherical, astigmatism (toric), bifocal, multifocal, keratoconus and orthokeratology. Spherical lenses) have a rounded shape and the correct myopia (nearsightedness) and hyperopia (farsightedness. Astigmatic correcting or toric lenses for astigmatism, especially, but also for nearsightedness and farsightedness, astigmatism, as may occur in both states. Bifocal lenses have two different zones for near and far. Multifocal lenses contain different zones for the provisionnear, intermediate and distance vision, a combination that results in very clear vision. Keratoconus lenses are specially designed to irregularly shaped cornea that distorts vision correct cause. Only these lenses can place the irregularity and provide a clear and comfortable solution. Orthokeratology lenses are designed to reshape the cornea while the wearer for, so that they be free lens during the day. In the United States, one of fivePeople who need to take the corrective vision lenses. Because contact lenses worn directly on the cornea, carriers generally find them to be more advantageous than glasses.
5 Reasons to wear contact lenses:
2) contact lens wearer can see that the quality of vision appears more natural. This advantage is especially important in sports and during the trip, when the peripheral vision and precision is the depth of fieldrequired.
3) contact lenses offer vision that is free of annoying obstacles and reflections.
4) Do not do fog lenses with varying ambient temperatures, yet they pose a constant adjustment, as is customary in glasses.
5) Although the majority of contact lenses are worn for vision correction, there are lenses are manufactured and distributed as cosmetic and therapeutic lenses. The cosmeticApplication is probably the most common. The carrier can improve the color or choose an opaque color contact lenses to fit their mood or wardrobe. Although colored contact lenses can be made available to someone who does not become necessary corrective measures vision requires a valid prescription for any type of contact lenses.
If you experience symptoms or side effects from wearing contact lenses should immediately get in touch with their eye carePractitioners. For more information about contact lenses and eye care from Contact Lens King's disposal.
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