Aspheric lenses feature varying curvature across their surface, unlike traditional soft lenses with a completely spherical design. Curvature varies more significantly towards the edges than it does in a spherical lens, which has a gradual curvature.
Aspheric lenses are generally more flexible than spherical lenses, where the value of curvature (BC) is the same at any point on the lens. Aspherical lenses are able to correct optical defects and provide sharper vision in the dark and at dusk because light is able to penetrate and meet at one focal point, rather than multiple. They are also helpful for those with low levels of astigmatism during sports or work with computers.