A sphere uses one curvature on the whole surface, just like cutting from a sphere. A non-sphere has different curvatures such as cutting from an ellipse. The main purpose of non-spherical is to solve the problem of spherical aberration, because the spherical surface has a different focus on off-axis light, resulting in blurred visual deformation. So, what's the difference between an aspherical lens and a spherical lens?
What is a spherical lens? Both sides of the spherical lens are spherical. The surface radian of each surface is uniform, with a single curvature radius. The processing equipment is simple, the price is cheap, the lens is thick, there is an aberration, and there will be obvious bad phenomena such as unclear image, deformation around the visual object, narrow field of vision, and so on.
What is an aspherical lens? Aspherical surface, as the name suggests, is not a sphere. Geometrically speaking, there is no unified spherical radius. Refraction is called curvature radius. So far, the design of the aspherical lens refers to the continuous change of the diopter from the optical center area to the edge, and its change curve is parabolic. And these determine that the luminosity of the lens decreases gradually from the optical center to the surrounding area. The aspheric cylindrical mirror is composed of photosensitive polymer and glass optical lenses. The polymer is coated on only one surface of the double lens, so it can be manufactured quickly in a short time, providing flexibility similar to that of a typical multi-element assembly.
In the traditional spherical lens, the objects around the lens are distorted, which limits the wearer's field of vision. In the era of continuous progress of science and technology, the optical miracle of aspheric design minimizes the edge aberration of the lens, so that its wide field of vision can meet the needs of customers. The aspherical lens has a smoother base bend, lighter weight, and looks more natural and beautiful. In the case of high diopter, it can reduce eye deformation. For consumers with high vision, it may be more appropriate to choose aspherical lenses.
The surface radian of an aspherical lens is aspherical. Compared with the spherical design lens, this design has the following advantages.
1. It is clearer. The aspherical lens with a unique coating treatment has perfect visual performance and presents clearer and comfortable visual effects.
2. It is easier. After wearing an aspherical lens, you can hardly feel its existence, which makes you feel more comfortable.
3. It is more natural. Aspheric design is more natural with less visual deformation. If you wear it, you will see more clearly.