an uncorrected visual acuity of at least 20/40 (6/12) with both eyes open. 9 m5 j1 E. I. Q& a$ I& ?7 q8 @visual aids (glasses or contact lenses) must have vision of 20:20 (6:6) with both eyes open. ! g1 w) r2 z5 |; ?; H) \
( w- [/ Q8 F$ q9 j5 r
请问上面的意思是什么?相当于国内什么等级的视力?谢谢!