Spherical Aberration Definition. A measure of the spherical aberration of the optical system is the physical distance between the foci of the reference sphere and of the peripheral rays of the aberrated wavefront. Aberration, in optical systems, such as lenses and curved mirrors, the deviation of light rays through lenses, causing images of objects to be blurred.

Linear chromatic aberration of lens the magnitude of longitudinal chromatic aberration produced by a convex lens for the pair of violet and red colours is 0.353 cm. Spherical aberration produces an image in which the centre of the field of view is in focus when the periphery may not be.