Contact lenses have been a boon for citizen with vision disabilities. They became beloved in the United States in the early 1970s, and since then, have caught the fancy of citizen worldwide. Today, there are prescribe palpate lenses, as well as palpate lenses for cosmetic purposes. There are a estimate of palpate lenses available with different designs for varied vision disabilities.
[b]Lens[/b]Soft palpate Lens Designs
There is a particular soft palpate lens institute available to suit a particular vision problem. It does not matter whether you are nearsighted or farsighted, you are suffering from astigmatism, or you need a bifocal prescribe for your presbyopia, your ophthalmologist can suggest the best palpate lens institute that fits with your definite need.
Spherical particular vision palpate Lenses - These are the most common and beloved type of soft palpate lenses available. They take care of your nearsightedness, and farsightedness (myopia, and hyperopia). Such rotund particular vision palpate lenses have the same power all along its curvature. The power of palpate lenses is expressed in units known as diopters (D).
As the power in all the meridians of the rotund palpate lenses is the same, it is expressed by a particular estimate to enumerate the lens. Soft rotund particular vision palpate lenses are made in the power increments of 0.25 D. For example: if your current palpate lens power is + 1.75 D, the next stronger power lens available will be + 2.00 D.
The power of the palpate lenses that strict nearsightedness is preceded by the minus (-) sign, whereas in the case of farsightedness, the power is preceded by the plus (+) sign. The soft rotund particular vision palpate lenses that have the power of - 1.50 D strict 1.50 diopters of nearsightedness. The power is at times, denoted as - 2.50 sph, or naturally - 2.50.
Soft Toric particular vision Lenses - These soft palpate lenses are used for the correction of astigmatism, in blend with whether farsightedness, and/or with nearsightedness. Astigmatism, quite a common condition, is caused by irregularities in the cornea or lens of the eye. Normally a hereditary condition, in astigmatism, the normal rotund shape of the cornea, or the lens, of the eye is more oblong.
To strict the irregularly shaped cornea of the eye, these soft palpate lenses have different powers in different lens meridians. The soft palpate lenses Normally rotate in the eye. In case of the rotund particular vision palpate lenses, it does not matter, as the power is the same all around its meridian. In the case of soft toric particular vision lenses for astigmatism, the lens has to be kept from rotating in the eye, as there are different powers for different meridians.
This is principal for a consistent clear vision, as the power of the lens must remain in front of the intended meridian. This is done by 'ballasting' - a extra law of weighting and different thicknesses in different lens meridians. This keeps the lens from rotating.
Two numbers enumerate the powers of the soft toric particular vision lenses - a sphere power (sph), and a cylinder power (cyl). The sphere powers can be preceded by either, a minus (-) sign, or a plus (+) sign, whereas the cylinder power is all the time in minus (-). In a prescription, the sphere power is all the time written first, followed by the cylinder power.
The prescriptions for toric soft lens consist of a third number, known as the 'cylinder axis'. This power is all the time preceded by
'x' and is also the last in the prescription. This axis denotes the location of the flattest meridian of the eye - the meridian that is for the sphere power - and its angle is measured in degrees.
Soft Bifocal Or Multi-focal Lenses - These soft palpate lenses have been designed to strict presbyopia, in blend with farsightedness, and/or with nearsightedness. Affecting adults over the age of 40, presbyopia is the normal age-related loss of near focusing ability.
The rotund power in the soft bifocal or multi-focal lenses strict nearsightedness or farsightedness. In addition, there are one or more magnifying powers for close-up vision. This further magnifying power, called the 'add power' is for the correction of presbyopia. The 'add powers', just as the sphere and cylinder powers in soft palpate lens prescriptions, are measured in diopters, and all the time preceded by the plus (+) sign. It has a range from +1.00 to +3.00 D.
The fit of the lenses and the size of the wearer's pupils are some of the factors on which the performance of the bifocal and multi-focal soft palpate lenses depends. citizen who use bifocal or multi-focal palpate lenses have a slightly reduced optical acuity as compared to when they use a normal particular vision palpate lenses for length vision, and a pair of glasses over their palpate lenses for near vision. Still, many are ready to overlook this slightly less clear vision for the capability to read without the need for reading glasses.
There is an alternate way by which presbyopia is corrected by using soft particular vision lenses - whether rotund or toric. This technique, called monovision, has soft lenses prescribed in such a way that one eye is optimized for length vision, and the other eye is optimized for near vision.
Contact lens wearers, uncomfortable with bifocal or multi-focal lenses, find monovision particular vision lenses better as far as vision clarity is concerned. The major benefit of using particular vision lenses in place of bifocal or multi-focal lenses is the affordability. The cost of particular vision lenses is significantly lower than that of bifocal or multi-focal lenses.
Contact Lens Designs for Keratoconus
Keratoconus - abnormal cone-shaped protrusion of the cornea of the eye - can be corrected by many different palpate lens designs. The ophthalmologist evaluates the requirements of each personel to prescribe a lens that offers the best blend of optical acuity, relax and corneal health. Each institute has its own unique characteristics, and no one institute suits all types of keratoconus.
Rigid lens designs, Normally spherical, achieve the best optical results. Aspheric lens designs are used in cases of small to moderate nipple cones, where it aligns with the more normal peripheral cornea.
The distinct Designs Of palpate Lenses available
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