About: http://webisa.webdatacommons.org/151819240

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	In this case, it is further preferable that at least one surface of the lens is an aspheric surface with a local radius of curvature that becomes smaller with increasing distance from the optical axis.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com