What is aspheric lens?

[Karissa Eyeglasses]

Im curious of what is Aspheric lens because i asked the customer service in cheapglasses123 that what kind of material they use for the lenses then she said Aspheric lens.
Im so shy to ask what is Aspheric im trying to tell her that i know that...

[Michaela Eyeglasses]

An aspheric lens or asphere is a lens whose surfaces have a profile that is rotationally symmetric, but is not a portion of a sphere.[1] In photography, a lens assembly that includes an aspheric element is often called an aspherical lens.

The asphere's more complex surface profile can reduce or eliminate spherical aberration and also reduce other optical aberrations compared to a simple lens. A single aspheric lens can often replace a much more complex multi-lens system. The resulting device is smaller and lighter, and possibly cheaper than the multi-lens design. Aspheric elements are used in the design of multi-element wide-angle and fast normal lenses to reduce aberrations.

[Mareli Eyeglasses]

Aspheric lenses are any lenses whose surface angles and profiles are neither part of a sphere nor part of a cylinder. Conventional or non-aspheric lenses have the same curve across their entire surface, like a ping-pong ball. Aspheric lenses accomplish the same amount of refraction but are flatter and slimmer.

[Giancarlo Eyeglasses]

Aspheric lenses are commonly used in photography, as well as in eyeglasses and contact lenses. In the context of photography, the complex surface profiles of aspheric lenses can eliminate the distortion of certain types of lines