Vector analysis of astigmatism. Adding and subtracting spherocylinders.
Retzlaff
J
J
Paden
P Y
PY
Ferrell
L
L
D001251:Astigmatism / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D002387:Cataract Extraction / Q000009:adverse effects; D006801:Humans; D008433:Mathematics