an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 8 [3 G' Y5 s" l5 r, g4 Jvisual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 7 z+ L) b( C6 G
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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!