Definitions for "Aberrations"
Imperfections in the visual or optical system that result in distortions and out-of-focus images.
Imperfections, irregularities and/or distortions of the optical quality of the eye that cause unclear vision
Keywords:  lens, failure, mirror, exact, perfect
the failure of a lens to give a perfect image
failure of a mirror or lens to produce an exact point-to-point correspondence between an object and an image of the object.
Deviation from the usual course or condition