Question

What is spherical aberration and how can it be corrected?

Answer 1

the inability of a lens of large aperture to bring all the parallel incident rays on the lens to focus at a point is known as spherical aberration

it can be correct by using stops or by replacing it with a suitable mirror

hope this helps

Answer 2

When the incoming light is passed through the spherical surface, it gets focused at various different points which causes a problem known as spherical aberration. It's mostly found in spherical surfaces of optical systems.

It can be corrected by using small aperture(black, left) to ensure that the image is formed only through the light passed through the center of lens.