What do you care most when buying eyeglasses lenses?
Actually, there are two kinds of basic lenses, spheric and aspheric,the former are used to correct the error induced by flattening the lenses by using a non-spheric lens shape; while the later is also called non-spheric lenses, which is a subclass of aspheric lens, and they are just known as high-index lenses, which can provide a stronger refractive index, accordingly, these lenses are much more expensive than ordinary ones! Aspheric lenses absolutely are good choice for high prescription, you will get the thinner lenses, especially for rimless frames.
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