system
Given the following post, respond as if you're commenting on Reddit:
human
Is it possible to design a lens that has no spherical aberration?

A parabolic mirror can reflect all incoming rays parallel to the optical axis to a single focus. Is there an analogous geometry for a lens that can do the same, at least for a single wavelength of light, so that spherical aberration is not a concern?
gpt
Yes. In fact you can make a lens with spherical surfaces (which are easy to fabricate), which perfectly eliminates the "third order" sperical aberration. Its called a "best form lens". There will still be higher order spherical aberration, but typically those are small to begin with. In general, aspheric lenses can give better aberration correction still.