Aberration

• aberrance: a state or condition markedly different from the norm
• a disorder in one's mental state
• an optical phenomenon resulting from the failure of a lens or mirror to produce a good image
• Any inherent deficiency of a lens or optical system. Aberrations are responsible for imperfections in shape or sharpness of the image.
• Abnormally deviant, abnormality, abnormal variant.
• A species that was not created naturally and/or was modified through various means.
• An inherent flaw - or deviation from a theoretical ideal - in a lens which leads to a degradation of some aspect of image quality. The most common forms are spherical aberration, coma, astigmatism, curvature of field, curvilinear distortion (barrel and pincushion) and chromatic aberration.