What is the name of the aberration that can induce cylinder power in a spherical lens?

Marginal astigmatism refers to a specific type of optical aberration that occurs due to the way light rays enter a lens. In a spherical lens, light rays that do not pass through the optical center can focus at different points, leading to cylindrical power being induced. This means that the lens does not bend all light rays uniformly, thus causing a distortion in the image.

Marginal astigmatism often arises from imperfections in the lens shape or misalignment, causing horizontal and vertical planes of focus to shift. This results in a lack of uniform sharpness across the visual field, which can impact vision quality. Correcting for this aberration is essential in optics to ensure clear and accurate image representation, especially in applications like glasses and contact lenses.

The other types of aberrations mentioned, such as radial astigmatism, chromatic aberration, and coma, have their own specific characteristics and effects on image quality but do not primarily induce cylinder power in spherical lenses in the same manner as marginal astigmatism.