A single-vision lens, also sometimes called a "unifocal lens", is a lens that has the same power of correction across its whole surface. It can be used to correct "simple" vision defects, such as myopia, hypermetropia and astigmatism. There are two types of single vision lens spherical surface lenses, which are suitable for everybody and aspherical surface lenses which is flatter and more aesthetic, they are particularly recommended for people who require a high correction.

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