About: http://webisa.webdatacommons.org/226731255

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	FIG. 2 is a graph depicting how astigmatism is related to the base curve ad the focal power in the visual angle of 30 degrees on a single vision lens;
http://www.w3.org/ns/prov#wasQuotedFrom	google.com