Aberration
From The Glossary of Digital Photography
A blurring or distortion of light rays through a lens. Abberation is created by imperfections that cause the rays to focus improperly. The different types of aberrations include monochromatic and chromatic aberrations, which can be further broken down into other types of aberration. Aberrations can show up in
images and are to be generally avoided. See also monochromatic aberration; chromatic aberration.
