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In the previous decades, you are not so lucky to wear high index lenses for a strong prescription correcting as today, you have the only choice to wear thick and heavy eyeglasses lenses, which will give you a feeling of uncomfortable and ugly appearance back, and people may lose the confidence when wearing them. So, there are two most disadvantages of these out dated lenses, one is its physical attribute, they are too heavy for individual’s nose bridge to bear it all day long; while the second one is they influence aesthetics, fashion is really an important element when people need to buy prescription eyeglasses lenses!
High index lenses may give you another opportunity to choose great looking glasses today. They are manufactured now with a different kind of material, the feature of optical quality is even better the old day’s glass and normal plastic lenses, but what’s more important is they are much lighter. There are usually two parameters to inspect the property of a lens, the refractive index of the lens and the eyeglasses curvature, let me explain the relationship between the two, the higher the refractive index of a lens is, the harder it can bend the light, then, the manufacture can make the minimum curvature, thinner lenses are based on the minimum curvature. Because such eyeglasses lenses can bend light harder, there needs to be less material to satisfy the same prescription, and the whole weight of lens decline to another level, and you will get a thinner pair.
People who are suffered from myopia get great benefit of wearing these high index lenses, they will give you a trendy look, and people in front of you cannot guess your real prescription as you are just looked wearing normal eyeglasses! What’s more, you can also choose to wear them if you get serious problem of near vision, as the thinning of lenses is at the center and it will not be visible, to solve the problem, manufactures provide us aspheric lenses now, people will get the purpose of both vision correction and cosmetic!
People need these very thin and flat prescription eyeglasses lenses to take place of those thick and heavy ones, however, high index can bend light harder, they both can block more lights that ordinary ones, and that’s the reason why many opticians provide anti-reflective coatings(AR coatings) for us, the can change the transmissivity as much as 98%! Moreover, most online sites provide such coatings free! |
