We explain what the term aberrations means

Unwanted effects visible in images, which form due to the construction of the lens. Some of these may be insignificant and only noticeable when images are viewed at their actual size.

Others, such as flare or ghosting, may be more obvious and can further affect an image by lowering contrast.

Lens elements with aspherical surfaces or low-dispersive properties are used in order to minimise these.