Phoria measurements using chromatic targets.
Von Graefe phoria measurements were obtained for ten prepresbyopic subjects at 40 cm and 6 m test distances using a vertical column of black letters on red, green, and white backgrounds. Phorias measured at 40 cm using red and white target backgrounds were similar, but the phoria measured using a green target background indicated a change toward greater exophoria. No difference in phoria measurements was found between all targets at 6 m.
D000065:Accommodation, Ocular; D003116:Color; D006801:Humans; D013285:Strabismus / Q000175:diagnosis*; D014787:Vision Tests / Q000295:instrumentation / Q000379:methods