Although taste lenses have been colse to for more than 100 years, contemporary contacts made of plastic rather than glass, were introduced in 1948. They are worn directly on the cornea of the eye and, if properly fitted, can furnish nearly natural vision.
[b]Lens[/b]The first plastic lenses were made of hard plastic called Pmma (polymethyl methacrylate) and did not deliver oxygen to the cornea. In 1971, soft contacts were introduced. Soft lenses are made from a water-loving or hydrophilic polymer that can bind up to 74 percent water. Soft contacts quickly substituted hard lenses in popularity, as they are ordinarily more comfortable for the wearer.
The silicone hydrogel lens entered the store in 1999, and have come to be the fastest growing taste lens segment worldwide. The material is resistant to dehydration and allows for a high oxygen transmission to the eye. taste lenses are a curative device, and as such, they must be prescribed and properly fitted by an eye care practitioner. They are grouped based on the material they are made of, distance of wear, frequency of disposal, and lens design.
Until the introduction of extended wear taste lenses in 1979, all contacts needed to be removed and cleaned nightly. Today, eye care professionals can designate an extended wear lens, which can be worn overnight for up to seven days without removal; a continuous wear lens, which can be worn for as long as 30 days without removal; and a daily wear lens, which must be removed every night.
The major disadvantage of taste lenses is that proteins and lipids, which are naturally found in tears, bind to its surface, making it prone to natural deposits, such as calcium. Eye ache and dryness can consequent from the deposits creating a water-rejecting film on the front exterior of the lens. The deposits can also furnish a source of nourishment for infection-causing bacteria. This makes it especially important to consequent the guidance of one's eye care practitioner with regard to lens care and replacement. The former function of a taste lens is to address the vision problem it has been prescribed to correct. Eye care professionals must work to find a lens that properly fits the eye of the patient, while inspecting other eye conditions the outpatient may have, such as dry eye.
Contact lenses come in some designs - spherical, astigmatic (toric), bifocal, multifocal, keratoconus and orthokeratology. Spherical lenses have a rounded shape and accurate myopia (near-sightedness) or hyperopia (far-sightedness). Astigmatic or toric lenses generally accurate for astigmatism, but also for myopia and hyperopia, as astigmatism can occur in both conditions. Bifocal lenses consist of two different zones for near and far vision. Multifocal lenses consist of some different zones providing for near, intermediate and distance vision, a mixture that results in clear vision throughout. Keratoconus lenses are specially designed to accurate irregularly shaped corneas, which cause distorted vision. Only these lenses can adapt the exception and furnish a clear and comfortable solution. Orthokeratology lenses are designed to reshape the cornea while the wearer sleeps, allowing them to be lens free during the day. In the United States, one out of five citizen who need vision correction wear taste lenses. Because taste lenses are worn directly on the cornea, wearers typically find them to be more beneficial than eyeglasses.
5 reasons to wear taste lenses:
2) The taste lens wearer may notice that the ability of vision appears more natural. This advantage is especially important in sports and while driving, when peripheral vision and accurate depth of field is necessary.
3) taste lenses furnish vision that is free of annoying obstructions and reflections.
4) taste lenses don't fog up with varying ambient temperatures, nor do they need constant adjustment, as is common with eyeglasses.
5) Although the majority of taste lenses are worn for vision correction, there are lenses that are artificial and distributed as cosmetic and therapeutic lenses. The cosmetic application is probably the most common. Wearers can pick a color enhancing or an opaque color taste lens to match their mood or wardrobe. Although color taste lenses can be made ready to someone who does not need medicinal vision, a valid designate is required to collect any kind of taste lens.
Anyone who experiences ache or side effects from wearing taste lenses should immediately get in touch with their eye care practitioner. Supplementary data with regard to taste lenses and eye care [http://www.contactlensking.com/eyehealth.aspx] is ready from taste Lens King.
A Brief History and Benefits of touch Lenses
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