What Is The Difference Between A Spherical Lens And An Aspheric Lens?

What is a spherical lens? What is an aspheric lens? What is the difference between the two? 

The spherical lens has a spherical surface, and the radius of curvature of the entire lens is the same. On the contrary, the surface of an aspherical lens is more complicated, and the curvature gradually changes from the center to the edge. These design differences can reduce the number of components in the assembly and result in thinner and lighter lenses.

The surface of a spherical lens looks like a part of a spherical or cylindrical surface.

The curve is the same across the entire surface. If you draw a straight line along the curve, it will form a circle. Due to the simple design, the design of spherical lenses is usually cheaper.

The surface of the aspheric lens must not be part of a sphere or cylinder. The curve of some parts of the lens surface changes to better focus the light. This change in the surface can correct various aberrations.

What is A Spherical Lens?

Imagine a transparent sphere with a circle in front of us. The surface of a sphere is a surface called a sphere. The spherical lens only means that one surface of the sphere is selected as the lens.

What is an aspheric lens?

Literally, it is easy to understand, this means that the lens is not spherical.

Aspherical Lens in Spectacle Lens

In terms of appearance, spherical lenses are "potbelly", but aspheric lenses are relatively flat, so from an aesthetic point of view, aspheric lenses look better. Aspheric lenses have many advantages. For example, aspheric lenses are precisely designed and optimized for lens power combinations, so they are thinner and more resistant to collisions than spherical lenses. Therefore, people with high magnification lenses usually wear aspheric lenses.

When you look at things through the lens, the difference will be more obvious. When looking around a spherical lens, distortion occurs. Due to the design of the aspheric lens, the aspheric lens can minimize the difference between the edges of the lens and see objects more naturally, with less distortion and more realism.

Aspheric lenses are very good, why do people choose spherical lenses?

For friends with mild myopia, spherical lenses and aspheric lenses are almost the same, there will be no aberration problems, and the lens thickness is similar. Considering the price factor, you can choose a spherical lens.

In addition, for a small number of people who are particularly sensitive to colors, if they wear aspheric lenses, they will feel rainbow phenomenon, so you can try to replace spherical lenses.