
A lens whose curved surface does not conform to the shape of a sphere; lenses are usually ground or molded with spherical surfaces; because a spherical surface lens has difficulty in correcting distortion in ultra-wideangle lenses or coma in large-aperture lenses brought about by spherical aberration, an aspherical lens is ...
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http://www.encyclo.co.uk/local/21048

A lens whose curved surface does not conform to the shape of a sphere; lenses are usually ground or molded with spherical surfaces; because a spherical surface lens has difficulty in correcting distortion in ultra-wideangle lenses or coma in large-aperture lenses brought about by spherical aberration, an aspherical lens is used.
Found on
http://www.rodsmith.org.uk/photographic%20glossary/rods%20photographic%20gl

A lens that has an aspherical (not spherical) surface. It is harder and more expensive to manufacture, but it offers certain advantages over a normal spherical lens such as a lower F number.
Found on
http://www.zoo.co.uk/~z0001325/Glossary.html

A lens with edges flattened so that it is not a perfect sphere. These produce a much superior image.
Found on
https://www.encyclo.co.uk/local/22122
No exact match found.