an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. ( f+ F! I) e$ W. {" O8 w0 @visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 6 N Z1 _; E0 O1 {0 j) V
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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!