an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. * l2 v& ^' m; q2 @/ ?5 dvisual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 8 ^2 M8 d3 v7 G( E+ S" T7 U4 ] D: \9 S+ ]- }$ l
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!