an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 2 ] u5 V' |# L4 ~/ Z/ G9 S
visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 5 N3 k/ `0 ]8 M5 e
( o2 S7 j. I% U
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!