an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. + n( y1 F2 l# M; h( i* |visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 6 `- c9 p3 M1 _1 n# u& P2 A/ C
+ E5 n5 _+ z( S) [ ^, f9 x
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!