1. Binocular astigmatism (?) Author(s): Richey, S. O. (Stephen Olin), 1849-1919 author Publication: [Chicago?] : [publisher not identified], [1888?] Subject(s): AstigmatismVision, Binocular
2. A simple and efficient test for binocular reading Author(s): Weiland, Carl, author Publication: [Philadelphia?] : [publisher not identified], [1894?] Subject(s): Vision, BinocularVision Tests -- instrumentation
