an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 7 R) T' K% f/ y% |0 y; [* X) J1 _visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. 2 u7 y8 Q3 H& m7 T0 M. W
- ^0 C" m9 d' R7 p9 I }* S
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!