Anastigmat
An anastigmat or anastigmatic lens is a photographic lens completely corrected for spherical aberration, coma, and astigmatism. Early lenses often included the word Anastigmat in their name to advertise this new feature. All modern photographic lenses are close to being anastigmatic.
The first Anastigmat was designed by Paul Rudolph for the Carl Zeiss AG in 1890.
Many telescopes are three-mirror anastigmat.
