About: http://webisa.webdatacommons.org/413536146

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	Also included in the apparatus is an optical system for producing a fixed-position image at one position in the user's visual field, and a series of transient images at different selected positions in the subject's visual field.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com