About: http://webisa.webdatacommons.org/165705706

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. 18 is a diagrammatic representation of an optical lens, having different refractive powers, which is uncovered by the iris for focusing the transmitted light.
http://www.w3.org/ns/prov#wasQuotedFrom	google.co.uk