an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. " S, C) K4 U/ j. m- \2 X. V+ }
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. ' }: ~) v9 E2 s6 f1 h7 @' g" C* m% G4 f
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请问上面的意思是什么?相当于国内什么等级的视力?谢谢!